Towards New Strategies for Investing: Insights on Sustainable Exchange-Traded Funds (ETFs)

Abstract

As investors increasingly incorporate environmental, social, and governance (ESG) factors into their decision-making, sustainable Exchange-Traded Funds (ETFs) have gained prominence in both investment portfolios and financial research. This study aims to provide a comprehensive analysis of the Sustainable ETF research landscape by utilizing scientometric and bibliometric methods with tools such as VOSviewer, Bibliometrix, and CiteSpace. Drawing from the Web of Science and Scopus databases, the study identifies key thematic areas, influential authors, and emerging trends. The findings highlight the conceptual evolution of Green ETFs, from early definitions focused on ESG-aligned investments to more complex instruments incorporating diversified screening criteria and advanced technologies like machine learning and artificial intelligence. Practical challenges such as regulatory inconsistencies, high implementation costs, and limited investor education are underscored as critical barriers to broader adoption. Future trends reveal the growing role of blockchain technology for ESG verification, crisis-specific ETF models, and the development of more inclusive screening strategies. Strategically, Green ETFs demonstrate resilience during market volatility and support sustainability-driven investment frameworks. The study provides valuable insights for investors, policymakers, and researchers, emphasizing Green ETFs’ role in driving sustainable finance and offering actionable guidance for optimizing ESG investment strategies.

1. Introduction

The intersection between financial markets with environmental, social, and governance (ESG) issues has become increasingly prominent in recent years, reflecting a growing recognition of the interconnectedness between sustainable practices and investment outcomes [1]. Within this context, the study of sustainable Exchange-Traded Funds (ETFs) has garnered significant attention as investors seek opportunities to align their investment strategies with their values while pursuing financial returns [2]. ETFs have emerged as a pivotal financial mechanism since their inception in 1993, providing investors with a versatile and efficient way to access diversified securities portfolios [3]. ETFs offer organizational flexibility, with options ranging from trusts to mutual funds. Notably, ETFs structured as mutual funds allow daily trading like stocks while benefiting from mutual fund diversification. One of the defining features of ETFs is their ability to facilitate in-kind transactions, minimizing transaction costs and capital gains. This attribute, combined with the ability to trade ETFs like stocks, enhances their appeal to investors seeking efficient, low-cost investment options [3].

Moreover, ETFs contribute significantly to sustainable finance by offering options aligned with environmental, social, and governance (ESG) criteria, reflecting the growing trend of socially responsible investing. Thus, Sustainable ETFs play a pivotal role in contemporary finance, providing investors with accessible and diversified investment opportunities, including those focused on sustainability. This is due to Sustainable ETFs offering a vehicle for investors to allocate capital towards companies and assets exhibiting positive ESG issues, thereby contributing to financial and sustainability objectives [4,5]. In this way, in recent years, ETFs have focused on topics related to ESG issues, sustainability, and green initiatives, which have yielded the highest returns for investors [6].

The importance of studying Sustainable ETFs lies in their potential to address pressing global challenges while generating competitive financial returns. By investing in companies and assets that prioritize environmental stewardship, social responsibility, and corporate governance, investors can mitigate risks associated with unsustainable practices and capitalize on opportunities presented by the transition to a more sustainable economy. Furthermore, Sustainable ETFs play a crucial role in advancing the United Nations Sustainable Development Goals (SDGs) by channeling investments towards initiatives to promote economic prosperity, social equity, and environmental sustainability [5,7].

Likewise, from a tendential perspective, one of the emerging topics in the investment world includes ETFs linked to ESG issues and sustainability [8]. Against this backdrop, the primary objective of this study is to provide a comprehensive analysis of the Sustainable ETF research landscape, focusing on their evolution, thematic areas, and emerging trends. To achieve this goal, the study addresses the following key research questions:

• ▪ RQ1: What are the prominent years of interest in Sustainable ETF research?
• ▪ RQ2: Who are the leading researchers in the Sustainable ETF field?
• ▪ RQ3: What thematic areas are observed in the scientific publication of Sustainable ETFs?
• ▪ RQ4: What are the principal thematic clusters in the Sustainable ETF arena?
• ▪ RQ5: Which topics are emerging and experiencing growth in the Sustainable ETF arena?

These research questions guide the analysis of the trends, knowledge diffusion networks, and collaborative contributions in the field of Sustainable ETFs; thus, by addressing these, the study aims to shed light on the evolution of Sustainable ETFs, highlighting the conceptual development of Green ETFs, from niche financial tools to essential instruments of sustainability-driven finance. The study also seeks to identify influential researchers, prominent themes, and knowledge diffusion patterns in the field. This analysis advances academic understanding and informs policymakers, investors, and stakeholders, fostering evidence-based decision-making and supporting sustainable finance principles in global financial markets.

By addressing these objectives, the scientometric and bibliometric analysis offers a holistic understanding of the research landscape surrounding Sustainable ETFs and their role as environmentally conscious investment vehicles. Furthermore, this study’s findings are poised to inform policymakers, investors, and stakeholders, facilitating evidence-based decision-making and advancing sustainable finance principles in the global financial ecosystem.

The paper is structured as follows. Section 2 details the research approach of scientometric and bibliometric methods. Section 3 presents the findings obtained through various scientometric methods, including knowledge maps, links, tables, and their analysis. Section 4 comprehensively discusses the empirical findings, highlighting Sustainable ETFs’ evolution, market impacts, and future perspectives. Finally, Section 5 summarizes the study’s main results and conclusions, offering practical insights for market participants, policymakers, and researchers interested in the dynamics of Sustainable ETFs.

2. Materials and Methods

2.1. Data Source, Search Strategy, and Processing

This study’s dataset has a wide range of studies discussing Sustainable ETFs sourced from the Web of Science (WoS) and Scopus databases. The selection of these databases enhances the breadth and reliability of the bibliometric analysis [9]. WoS was chosen for its comprehensive coverage of specialized sources within its core collection and its focus on high-impact core publications, which researchers in bibliometric and scientometric analyses commonly utilize. Scopus, on the other hand, offers a broader scope and access to a wider range of journal content, thereby supplementing the coverage provided by WoS. Together, these databases capture green finance research’s interdisciplinary and global nature [10,11].

The study’s objectives justify the scientometric approach over alternative methods, such as meta-analysis. Scientometric analysis allows for a quantitative examination of research trends, knowledge diffusion, and collaborative networks, offering a more holistic view of the evolution and structure of Sustainable ETF research. This approach is particularly suitable for identifying key thematic areas, leading contributors, and emerging research clusters, which aligns with the study’s aim to map the current state and future direction of Sustainable ETF research. By employing evidence-based methodological choices, the study addresses potential concerns regarding aligning its methods with its research objectives, thereby enhancing the robustness and credibility of the analysis.

Data collection occurred on 23 March 2024, from both datasets. The search strategy employed the term [“(TITLE-ABS-KEY (etf* OR “exchange-traded fund*” OR “exchange traded fund*”) AND TITLE-ABS-KEY (sustainab*))”], with a requirement for the term to appear in the title, abstract, and keywords of the studies. The search yielded 34 studies in WoS and 54 in Scopus within the targeted research area. Limiting the search to these specific sections helps ensure that the identified studies are directly relevant to Sustainable ETFs. By including these sections in the search criteria, we target studies where Sustainable ETFs are likely to be a focal point of discussion or analysis. This approach enhances the relevance and accuracy of the dataset, contributing to the robustness of the research findings. A comparison of data from both sources identified 28 duplicate studies, resulting in a final dataset of 60 unique studies. Figure 1 illustrates the literature search methodology employed.

2.2. Analytical Methods and Tools

Scientometrics and bibliometrics are closely related metrics fields that have evolved with distinct focuses and applications [12]. Despite their differences, these disciplines share common principles, methods, and tools and are often referred to collectively as two metrics in the research arena. Bibliometrics primarily examines numerical and pattern-based aspects of bibliographic data, such as paper counts and library usage. On the other hand, scientometrics quantitatively analyzes scientific information production, dissemination, and the understanding of scientific research mechanisms [13]. The development of these disciplines has been shaped by advancements in science and technology, including the rapid growth of digital and network technologies and the emergence of the knowledge economy [12]. As a result, there has been a convergence among these fields, leading to new research areas.

These techniques play a crucial role in understanding the dynamics of scientific research and information dissemination. Thus, researchers can analyze trends, identify key contributors, and uncover emerging topics within specific domains by applying mathematical and statistical methods. Moreover, these provide valuable insights into the evolution of scholarly literature and its impact on various fields, including science and technology policy, research collaboration, and regional aspects of science [13]. In summary, bibliometrics and scientometrics are interdisciplinary fields that contribute to understanding scientific studies, dissemination, and the knowledge frontier.

Understanding the nuances and relationships among bibliographic and scientometric techniques is essential for researchers and practitioners in order to have a broader understanding of any research topic. Figure 2 concisely overviews these two techniques’ differences, similarities, and interdisciplinary connections, highlighting their contributions to studying leading research topics.

As mentioned above, this study employs VOSviewer, Bibliometrix, and CiteSpace to conduct bibliometric and scientometric analyses. VOSviewer, widely employed in analysis across diverse domains, encompasses several standard scientometric and bibliometric features, including bibliographic coupling, co-authorship, co-occurrence, and co-citation analyses [14]. Bibliometrix, proposed by [15], facilitates the bibliometric and scientometric analysis due to the capacity for identifying and illustrating evolutionary trends within a specific subject area, offering capabilities for uncovering research progress, current frontiers, and knowledge foundations. Meanwhile, CiteSpace, an essential tool in scientometric analysis developed by [16], facilitates the visualization and analysis of emerging trends, influential authors, and key research themes through the generation of temporal evolution maps, co-citation networks, and keyword co-occurrence networks, including burst detection. By integrating these techniques, this study gains a holistic understanding of the dynamics and evolution of Sustainable ETF literature, contributing to informed decision-making processes and advancing scholarly understanding in the field.

3. Scientometric and Bibliometric

Incorporating scientometric and bibliometric analyses using tools like VOSviewer software version 1.6.20, Bibliometrix package for R, and CiteSpace software version 6.3.R1 Basic offers a significant opportunity to enhance the understanding of Sustainable ETFs. Ref. [17] emphasizes the importance of utilizing these tools effectively to provide novel insights rather than descriptive content. Complementing these guidelines, ref. [18] provides an overview of the bibliometric methodology, highlighting its utility in business research for handling large volumes of scientific data and producing high research impact. By establishing clear aims for the review and selecting appropriate bibliometric techniques, researchers can unlock valuable insights into the evolution and structure of the field. Integrating bibliometric methods with other systematic review approaches amplifies the impact of research by synthesizing existing studies and guiding future research directions. While bibliometric approaches serve to identify significant new insights, scholars must invest time and effort in interpreting findings thoughtfully to ensure meaningful contributions to the field. By addressing these challenges and leveraging the full potential of bibliometric tools, researchers can navigate the complexities of Sustainable ETF research and contribute to a robust research agenda.

Next, scientometric and bibliometric analyses are conducted to elucidate patterns and trends in the Sustainable ETF arena, aiming to uncover key insights into the dynamics of environmentally conscious investment vehicles. This analysis will shed light on various aspects, such as publication trends, author contributions, citation networks, and thematic clusters, providing a comprehensive understanding of the research landscape surrounding Sustainable ETFs.

3.1. General Information

Table 1. Overview of bibliographic data characteristics, Source: Authors’ own research based on Bibliometrix tool with data sourced from Scopus and WoS datasets.

Description	Results	Description	Results
Main Information About Data		Document Contents
Timespan	2005–March 2024	Keywords Plus (ID)	213
Sources (journals, books, etc.)	46	Author’s Keywords (DE)	209
Documents	60	Authors
Annual growth rate %	11.57	Authors	121
Document average age	3.68	Authors of single-authored docs	16
Average citations per doc	8.533	Document Types
References	1581	Article	42
Authors Collaboration		Article; early access	4
Single-authored docs	16	Book	3
Co-authors per doc	2.33	Book chapter	4
International co-authorships %	15	Conference paper	4
		Editorial material	2
		Review	1

provides a comprehensive overview of the dataset used in the analysis, covering various dimensions of its primary information, document contents, authors, authors’ collaboration, and document types. From 2005 to March 2024, the dataset encompassed data from 46 diverse sources, including journals, books, and other scholarly materials, comprising 60 studies. The dataset exhibits a notable average annual growth rate of 11.57%, indicating a dynamic and evolving field of study. Despite this growth, the average age of documents remains relatively low at 3.68 years, suggesting ongoing research activity and currency within the field. Each study garners an average of 8.533 citations, reflecting the scholarly impact and significance of the included works. Furthermore, the dataset contains several references, totaling 1581, underscoring the depth and breadth of the literature surveyed.

Regarding document contents, the dataset encompasses a diverse array of keywords, with 213 unique Keywords Plus (ID) and 209 Author’s Keywords (DE) identified within the documents. This diversity highlights the multifaceted nature of the research topics and the various dimensions explored by scholars in the field. Regarding authorship, the dataset involves 121 unique authors contributing to the documents, with 16 studies authored by a single author. Collaboration among authors is evident, with an average of 2.33 co-authors per study, reflecting a trend toward collaborative research endeavors. Moreover, approximately 15% of the studies involve international co-authorships, indicative of global collaboration and knowledge exchange within the field.

Regarding study types, the dataset comprises a range of scholarly outputs, including articles, book chapters, conference papers, editorials, and reviews. Articles represent the majority of the documents, with 42 articles included in the dataset, followed by articles with early access (4), books (3), book chapters (4), conference papers (4), editorials (2), and reviews (1). This diversity of document types underscores the interdisciplinary nature of the research area and the multifaceted approaches scholars adopt in investigating ETFs and related topics. Overall, Table 1 provides valuable insights into the composition and characteristics of the dataset, facilitating a deeper understanding of the research landscape and informing future scholarly endeavors in the field.

3.1.1. Annual Scientific Production

Figure 3 depicts the number of studies published on Sustainable ETFs annually from 2005 to March 2024. This shows a notable increase in academic interest and research output over the years. From 2005 to 2011, there were sporadic publications, with only one or two studies per year. However, starting in 2014, there was a noticeable uptick, with two to four publications annually. The trend continued to escalate from 2018 onwards, with a substantial publication surge each year. Particularly noteworthy is the exponential growth observed from 2022 to 2023, with the number of studies almost doubling within a year. This indicates a significant shift in scholarly attention towards Sustainable ETFs, possibly reflecting the growing importance and recognition of environmentally and socially conscious investment vehicles in contemporary finance and academia.

3.1.2. Analysis of Sources

Figure 4a,b provide valuable insights into the academic research landscape on Sustainable ETFs. Figure 4a depicts the distribution of studies across various journals over time, highlighting the breadth of academic outlets contributing to the discourse on this topic. Notably, the Journal of Sustainable Finance & Investment emerges as the leading source, indicating a dedicated focus on Sustainable ETFs within the realm of finance and investment. This suggests a growing interest in exploring the intersection of sustainability and financial markets within academic circles.

On the other hand, Figure 4b delves into the citation counts for studies published in different journals, shedding light on the impact and influence of research within Sustainable ETFs. Here, leading finance journals such as The Journal of Finance, Journal of Banking & Finance, and Journal of Financial Economics stand out, commanding the highest citation counts. This underscores the significance of research published in these journals in shaping discussions and driving advancements in understanding Sustainable ETFs.

The contrast of these figures reveals a notable correlation between the publication volume and citation impact across different journals. While certain journals, such as The Journal of Finance, demonstrate a high publication volume and substantial citation counts, others may have a relatively lower publication output but still wield significant influence within the academic community, as evidenced by their citation counts. This highlights the multifaceted nature of academic impact within the Sustainable ETF field, encompassing both the width of publication sources and the depth of scholarly influence.

3.2. Most Prolific Countries and Institutions

3.2.1. Countries

Figure 5a presents an insightful overview of research collaboration patterns among countries in the field under study. Notably, Romania emerges as a prominent contributor, with a relatively high number of studies produced compared to other countries. This suggests a growing interest and investment in research within the country. Similarly, the United Kingdom and the United States exhibit substantial production, reflecting their well-established research infrastructure and commitment to scientific advancement. The presence of these leading countries underscores their pivotal role in shaping the discourse and progress of the field on a global scale.

Furthermore, Figure 5a reveals intriguing research collaboration trends, particularly in countries like Spain, Kazakhstan, and Pakistan. Despite its lower study count, Spain demonstrates a notable commitment to international collaboration, as evidenced by its equal distribution of single-country and multi-country partnerships. This indicates a concerted effort to engage with researchers and institutions worldwide, potentially enriching the research output’s diversity of perspectives and expertise. On the other hand, countries like Kazakhstan and Pakistan rely heavily on multi-country collaborations, suggesting a need for external expertise and resources to bolster their research efforts. These partnerships likely facilitate knowledge exchange and capacity building, contributing to advancing research agendas in these regions.

On the other hand, Figure 5b shows the total citation (TC) counts for the most cited countries in the field. The United States leads with 77 citations, followed closely by Canada with 76 citations. Spain and Romania also have notable citation counts, with 65 and 39 citations, respectively. Countries such as Finland, Switzerland, the United Kingdom, Pakistan, and the Netherlands also have varying citation counts, ranging from 35 to 17. The high citation counts for leading countries like the United States and Canada underscore the significant influence of their research output, indicating its widespread recognition and contribution to advancing knowledge in the field. This recognition suggests that studies originating from these countries are considered authoritative and impactful within the global research community.

Additionally, countries such as Spain, Romania, Finland, and others with notable citation counts, as shown in Figure 5b, reflect diverse research activity worldwide. This diversity signifies international collaboration and knowledge dissemination, which shape the field’s progress. It demonstrates that Sustainable ETF research is not limited to a few dominant countries but rather encompasses a global network of researchers contributing to the collective understanding of the topic. Finally, countries like Romania, Finland, and Pakistan showcase emerging research hubs despite having relatively lower citation counts. Their notable contributions suggest growing research interest and investment, hinting at future potential for impact as research capacities develop. This highlights the evolving landscape of Sustainable ETF research and the emergence of new centers of excellence that have the potential to shape the field’s trajectory in the coming years.

Varied citation counts among countries highlight opportunities for collaboration and knowledge exchange. Collaboration between countries with differing citation counts can leverage expertise and resources, enhancing research quality and impact globally. It underscores the importance of fostering collaborative networks and partnerships to address complex research questions and drive innovation in Sustainable ETFETF research globally.

3.2.2. Institutions

Figure 6a illustrates the distribution of studies on Sustainable ETFs across various academic institutions. Notably, the University of Rome Tor Vergata, alongside other institutions such as the German University in Cairo, Instituto Politecnico de Tomar, and Tuscia University, has actively contributed to this area of research, each producing two to three studies. Additionally, institutes like Aston University, the Institute of Solid Mechanics of the Romanian Academy, Missouri State University, RWTH Aachen University, and Symbiosis International University have also demonstrated significant engagement, with each institution producing two studies. This collective effort signifies a growing interest and involvement from academic communities worldwide in exploring environmentally conscious investment vehicles like Sustainable ETFs.

Figure 6b presents a clustering of universities based on their collaborative efforts in academic production concerning Sustainable ETFs. Cluster 1 comprises five universities: Aston University, Heriot-Watt University, University of Cambridge, University of Kent, and University of Leeds. This suggests a collaboration network among these institutions in conducting research and publishing studies related to Sustainable ETFs. Such collaborations likely foster knowledge exchange, interdisciplinary perspectives, and collective advancements in understanding and addressing challenges in the field of environmentally conscious investment vehicles.

3.3. Most Relevant Authors

Table 2. Top ten most relevant researchers by citations on Sustainable ETFs. TGC: total global citation; TCTs: total citations in the topic; NP: number of publications; PY start: publication year start. Source: compiled from our research utilizing the Bibliometrix tool, with data sourced from Scopus and WoS datasets.

#	Researcher	Institution (Country)	h_Index	TGC	TCTs	NP	PY Start
1	Amr ElAlfy	Qatar University (Qatar)	4	281	78	1	2022
2	Leah Feor	University of Waterloo (Canada)	1	78	78	1	2022
3	Zachary Folger-Laronde	University of Waterloo (Canada)	1	78	78	1	2022
4	Sep Pashang	University of Waterloo (Canada)	1	81	78	1	2022
5	José Luis Miralles-Quirós	University of Extremadura (Spain)	14	765	64	2	2019
6	Maria del Mar Miralles-Quirós	University of Extremadura (Spain)	15	903	64	2	2019
7	José Manuel Nogueira	Instituto Politécnico de Tomar (Portugal)	3	75	64	2	2019
8	Maria Eugenia de Boyrie	Florida International University (United States)	10	334	55	1	2022
9	Ivelina Pavlova	University of Houston (United States)	8	254	55	1	2022
10	Rareş Halbac-Cοtοara-Zamfir	Universitatea Politehnica Timisoara (Rumania)	11	359	36	1	2019

presents a compilation of the ten highly cited researchers in the Sustainable ETF field, along with their affiliations and pertinent details based on [10]. These researchers are arranged in descending order based on their total citations in the topic (TCTs), offering insights into the most impactful contributors to Sustainable ETFETF research. This analysis utilized Scopus data to gather the total global citation (TGC) indicator and compared it with the TCT metric derived from Bibliometrix in R. The objective was to discern the areas where these researchers wield significant influence. Consequently, Table 2 delineates the top 10 researchers who have contributed substantially to exploring Sustainable ETFs from 2005 to 2024.

Recent research on Sustainable ETFs has shown promising developments, as indicated by the increasing number of citations in this topic, as shown in Table 2. This table highlights the researchers’ contributions and their impact on the field. Notably, Maria del Mar Miralles-Quirós, José Luis Miralles-Quirós, Rareş Halbac-Cοtοara-Zamfir, and Maria Eugenia de Boyrie have demonstrated substantial influence with their work, reflecting the growing interest in Sustainable ETFs. Additionally, recent researchers, such as Amr ElAlfy, Leah Feor, Zachary Folger-Laronde, and Sep Pashang, suggest a burgeoning interest in this area, indicating its relevance and potential for further exploration.

It is important to note that the most prolific researcher identified on the topic of Sustainable ETFs is Maria del Mar Miralles-Quirós. Her most cited study is [19], with 114 citations. This examines the relationship between ESG performance and stock prices in the banking industry, particularly in Brazil. This examines the impact of ESG performance on commercial banks listed at 20 different stock prices from 2002 to 2015 and reveals that while stock market investors attribute varying levels of value relevance to the three ESG pillars, the significance of ESG performance is notably higher for banks from common law countries and particularly pronounced after the global financial crisis. These findings underscore the evolving role of ESG issues in shaping investor perceptions and have important implications for stakeholders such as managers, investors, and market regulators in understanding the relationship between sustainable practices and stock market valuations.

The common topics in the studies conducted by Maria del Mar Miralles-Quirós include the following:

• ▪ ESG performance and financial value: Several studies, such as Miralles-Quiros, Miralles-Quiros, and Arraiano [20,21], explore the impact of ESG issues on firm value and stock market performance. Topics related to ESG performance and shareholder value creation, sustainability indices, and the profitability of using SDGs are prevalent.
• ▪ Financial markets and asset pricing: Another common theme concerns financial markets, asset pricing, and investment strategies. Studies like [22,23] analyze aspects such as abnormal profitability, investment strategies during crises, asset pricing models with asymmetric risk, and the role of liquidity in asset pricing.
• ▪ International diversification and portfolio optimization: Several studies [5,24] also focus on international diversification benefits for investors, portfolio optimization strategies, and the performance evaluation of ETFs in different market conditions. Topics related to the international diversification of portfolios, risk-minimizing portfolio strategies, and improving diversification opportunities for socially responsible investors are recurrent.
• ▪ Corporate governance and sustainable finance: Some studies delve into corporate governance practices, the role of boards in corporate green bond issuance, and the limits of gender policies on corporate boards in promoting sustainable development [25,26]. Topics related to corporate reputation, sustainable finance, and the assurance of sustainability reports also emerge frequently.

Overall, Maria del Mar Miralles-Quirós’ research covers a wide range of topics within the realm of finance and sustainability, focusing on understanding the relationship between ESG performance, financial markets, and investment strategies. Her studies contribute valuable insights into the sustainable finance arena, corporate governance, and asset pricing. Notably, most of her studies are co-authored with José Luis Miralles-Quirós, indicating a collaborative approach to research and a shared commitment to advancing knowledge in these areas.

3.4. Historiography Map

The historiographic map, developed by [27], visually represents the chronological connections among cited works, offering insights into the field’s historical evolution. This method, discussed in [15], helps analyze the temporal dynamics of scholarly influence and the interrelationships between seminal works. According to [28], historiography maps show how ideas move from study to study, as demonstrated in our analysis with a single cluster in red (Figure 7).

The research on Sustainable ETFs has garnered increasing attention recently as investors seek avenues to align their investments with ESG issues while aiming for financial returns. In particular, the timeline depicted in the historiographic map (Figure 7) originates with [4], who initiated this discourse by investigating Green ETFs, defining them as index funds replicating market indices invested in stocks exhibiting positive ESG issues. They proposed a market-wide proxy for green returns and volatility, shedding light on the time-series behavior of these investment vehicles and their associated conditional volatility dynamics. Likewise, refs. [5,7] extended this inquiry into the realm of SDGs, exploring the benefits of integrating SDG-focused ETFs into investment portfolios. Their research emphasized the potential for improved portfolio performance and the importance of focusing investments on specific SDGs. In this same line, ref. [29] contributed insights into the diversification benefits of SDG-focused ETFs, highlighting the varying impacts across different SDGs on portfolio efficiency. Moreover, the author emphasized the potential of SDG-aligned ETFs to enhance reward–risk ratios, particularly for strategic investors.

In light of the COVID-19 pandemic, refs. [6,30] examined the resilience of responsible investments, including ETFs, during market downturns, with differing conclusions regarding the efficacy of sustainability ratings in safeguarding investments. Ref. [31] provided further evidence of the diversification benefits of Green ETFs, particularly in the energy sector, while [32] evaluated the risk-adjusted returns of ESG ETFs before and during the pandemic-induced market crash. Ref. [33] explored the link between corporate social responsibility (CSR) and corporate financial performance (CFP), shedding light on the performance of ethical ETFs relative to conventional counterparts.

Furthermore, Refs. [34,35] delved into the performance of socially responsible ETFs during market downturns, emphasizing their resilience and potential for outperformance. Refs. [36,37] examined the impact of climate change and sustainability factors on ETF performance, while [38] analyzed the connectivity and spillover effects of climate uncertainty policy on ETFs. Ref. [8] provided a comprehensive bibliometric review of ETF research identifying emerging trends in passive investments. Finally, ref. [39] investigated the performance of portfolios incorporating green asset ETFs, demonstrating their potential to yield better outcomes for investors.

Then, based on the historiography, we can draw several findings:

• The research indicates a rising interest in Sustainable ETFs as investors increasingly seek investment options aligned with ESG issues while aiming for financial returns [4].
• Over time, the research on Sustainable ETFs has evolved from initial research into Green ETFs to a broader exploration of SDGs and their integration into investment portfolios [5,7].
• Several studies highlight the diversification benefits of SDG-focused and Green ETFs, suggesting potential improvements in portfolio performance and risk-adjusted returns, particularly for strategic investors [29].
• Research has examined the resilience of responsible investments, including ETFs, during market downturns such as the COVID-19 pandemic. While some studies suggest that sustainability ratings may safeguard investments, others offer differing conclusions [6,30].
• Studies indicate that socially responsible ETFs demonstrate resilience and potential for outperformance during market downturns, emphasizing their attractiveness to investors seeking stability and long-term sustainability [33].
• Researchers have explored the impact of climate change and sustainability factors on ETF performance, highlighting the interconnectedness between environmental policies and investment outcomes [36,37].

Overall, the research suggests that portfolios incorporating Green Asset ETFs have the potential to yield better outcomes for investors, indicating a promising avenue for sustainable and socially responsible investing in the financial markets [39].

3.5. Reference Analysis

Table 3. Top 10 cited studies in the research of Sustainable ETFs. Source: compiled from our research utilizing the Bibliometrix tool, as well as Scopus and WoS datasets.

#	Author	Source	Total Citations	TC per Year	Normalized TC
1	Folger-Laronde et al. [30]	Journal of Sustainable Finance & Investment	78	25.33	3.26
2	Miralles-Quirós et al. [5]	Business Strategy and the Environment	64	12.80	2.81
3	Pavlova and de Boyrie [32]	Finance Research Letters	55	18.33	2.36
4	Hălbac-Cotoară-Zamfir et al. [40]	Science of The Total Environment	36	6.00	2.25
5	Dutta and Dutta [41]	Renewable Energy	35	11.67	1.50
6	Sornette and Cauwels [42]	Risks	35	3.18	2.00
7	Naqvi et al. [31]	Energy Economics	27	9.00	1.16
8	Weston and Nnadi [33]	Journal of Sustainable Finance & Investment	22	11.00	8.80
9	Anderson [43]	Handbook of Environmental and Sustainable Finance	21	2.33	1.00
10	Miralles-Quirós et al. [7]	Sustainability	19	3.80	3.50

showcases the highly referenced research works within the Sustainable ETF field, highlighting specific studies garnered notable recognition and citations from fellow researchers. The identified studies collectively contribute to understanding Sustainable ETFs from various perspectives, including financial performance, environmental and social impacts, geopolitical influences, and policy implications. They underscore the importance of considering sustainability factors in investment decision-making and offer insights into the opportunities and challenges associated with integrating ESG issues into investment strategies.

The results reveal that the study conducted by [30] is the most cited in the Sustainable ETF arena. This contributes to the advancement of Sustainable ETF analysis by examining the correlation between ETF financial returns and their eco-fund ratings during the financial market crash caused by the COVID-19 pandemic. Their findings indicate that elevated levels of ETF sustainability performance do not automatically shield investments from financial losses during significant market downturns. This underscores weaknesses in existing sustainability scores and rating methodologies, offering an initial examination of responsible investments during crises.

In the second place, the study conducted by [5] enhances the comprehension of Sustainable ETFs by assessing the advantages of incorporating SDG ETFs into a stock–bond portfolio and evaluating various strategies’ out-of-sample performance. Their findings illustrate that investing in ETFs that track companies focused on advancing the SDGs can enhance portfolio performance, particularly in areas like decent work and economic growth, offering valuable insights for both researchers and investors. The authors of [5] are listed in Table 3.

Third, ref. [32]’s study contributes to the knowledge frontier of sustainable investment performance by analyzing the risk-adjusted returns of ESG ETFs before and during the COVID-19 market crash. Their study reveals that while higher sustainability ratings of ESG ETFs did not shield against losses during the downturn, they also did not underperform the market, providing nuanced insights into the performance of Sustainable ETFs during crises. The researchers Pavlova and de Boyrie [32] are listed third in the Table 3.

Additionally, Refs. [40,43] delve into the influence of political, socio-economic, and cultural factors on Sustainable ETF implementation. While [40] focuses on the historical context in Romania, ref. [43] discusses the emerging role of environmental finance globally, including the development of products like green bonds and debt-for-nature swaps.

Furthermore, ref. [41] examines the impact of geopolitical uncertainty on the volatility of renewable energy ETFs, highlighting the role of geopolitical risk in shaping investor behavior and asset prices. Additionally, ref. [33] investigates the link between corporate social responsibility (CSR) and corporate financial performance (CFP), focusing on ethical ETFs and the performance of firms following responsible investing principles. Their study adds a strategic management perspective to Sustainable ETF analysis, emphasizing the importance of CSR in investment decision-making.

Finally, ref. [42] offers a broader perspective on financial market dynamics, tracing the roots of economic crises and advocating for a shift towards more sustainable economic practices. Their analysis encompasses historical, economic, and policy dimensions, providing a comprehensive view of modern financial systems’ challenges. In summary, the findings from the analyzed studies shed light on various aspects of Sustainable ETFs and their implications for both financial markets and broader socio-economic contexts.

3.6. Keyword Analysis

Figure 8 shows the most common keywords and Keywords Plus identified in our study about Sustainable ETFs. Six distinct clusters of keywords were identified.

3.6.1. Cluster 1 Financial and Economic Aspects (Red)

This cluster focuses on various financial and economic aspects related to Sustainable ETFs, such as clean energy, renewable energy, green finance, and portfolio optimization. These aspects are vital for understanding the investment landscape and opportunities within the Sustainable ETF markets. For example, clean energy and renewable energy highlight the growing importance of environmentally friendly investments, while portfolio optimization underscores the need for efficient asset allocation strategies. Additionally, aspects like fossil fuel, oil prices, and shocks emphasize the influence of external factors on financial markets and the significance of risk management in Sustainable ETF investing.

3.6.2. Cluster 2 Behavior and Governance (Green)

This cluster’s keywords focus on behavioral aspects, climate change, and governance within Sustainable ETFs. Understanding investor behavior, financial performance, and risk disclosure is crucial for designing sustainable investment strategies that align with environmental and social goals. Terms like green bonds, mutual funds, and sustainable investments highlight investment vehicles’ increasing popularity and diversity in the Sustainable ETF markets. Moreover, this cluster highlights the importance of including ESG issues in investment decisions.

3.6.3. Cluster 3 Risk Modeling and Management (Blue)

This cluster delves into risk modeling, financial risks, and environmental factors impacting Sustainable ETFs. Environmental risk modeling, extreme value theory, and risk analysis highlight the need to assess and manage environmental risks associated with sustainable investments. Additionally, terms like systemic risk and healthcare risk underscore the interconnectedness of various risk factors and the potential implications for Sustainable ETF performance. Understanding these risks is essential for investors to make informed decisions and mitigate potential losses.

3.6.4. Cluster 4 Diversification and Social Responsibility (Yellow)

This cluster emphasizes the benefits of diversification and integrating socially responsible functions into Sustainable ETFs. Diversification benefits and socially responsible investment underscore the potential financial advantages and ethical considerations of incorporating sustainable principles into investment portfolios. Equilibrium and portfolios highlight the importance of achieving balance and diversification in Sustainable ETF construction, while returns and sustainable development underscore the dual objectives of generating financial returns and promoting sustainable practices.

3.6.5. Cluster 5 Risk Management and Corporate Responsibility (Purple)

This cluster focuses on risk management and corporate social responsibility within Sustainable ETFs. Terms like risk management and volatility underscore the importance of effectively managing investment risks, especially in the face of external factors like COVID-19. Additionally, corporate social responsibility highlights the growing emphasis on ethical business practices and integrating social and environmental considerations into investment decisions.

3.6.6. Cluster 6 Investment Funds and Performance (Light Blue)

Keywords in this cluster revolve around investment funds and performance within the context of Sustainable ETFs. Understanding the performance of investment funds is crucial for evaluating the effectiveness and impact of Sustainable ETFs in achieving their financial and environmental objectives. By analyzing investment performance, investors can assess the potential returns and risks associated with Sustainable ETFs, thereby informing their investment decisions.

3.7. Keywords and Reference Analysis

Developed by Professor Chen Chaomei at Drexel University in the United States, CiteSpace is known for its strong ability to analyze how documents relate [16]. In this study, we looked at how well CiteSpace could organize information using two main measurements: modularity (Q value) and weighted mean silhouette (S value), which help understand how information is organized and how clear the groups are. Modularity (Q) indicates how strong the groups of related information are, with numbers from 0 to 1. If the Q value is over 0.3, it means there are clear groups. The weighted mean silhouette (S) shows how well the groups are formed, with S > 0.5 being fine and S > 0.7 being very good [44].

In this study, we found that the keyword groups had a Q value of 0.8792, which shows that there are groups, as shown in Figure 9. The S value was 0.9843, which is more than enough for good grouping at 0.7. The average silhouette value was 0.9288, confirming that the groups were well formed. These strong groupings, with a clear structure and high effectiveness, are significant for fully understanding the main features and trends in Sustainable ETF research.

These groups have insights into leading research topics, such as diversification benefits, environmental issues, and renewable energy. These detailed groupings allow an understanding of the aspects of Sustainable ETFs and provide a complete picture of the important topics and their connection.

3.7.1. Cluster 1 Diversification Benefits (Orange)

This cluster explores the diversification benefits of incorporating various assets into investment portfolios, including commodities and renewable energy investments. Ref. [45] conducted an in-depth analysis of the impact of adding commodities to traditional stock–bond portfolios. The study evaluates different asset allocation strategies and commodity groups, revealing that the benefits of commodities may be overstated in previous analyses. The findings suggest that while certain commodities, such as aggregate commodity indices and metals, may enhance portfolio performance, others, mainly agricultural and livestock commodities, may not offer significant advantages in terms of diversification. Ref. [46] shift the focus to renewable energy investments within the Italian electricity market. The paper assesses the profitability of investing in renewable energy technologies for electricity production and highlights the economic factors influencing these investments. By applying portfolio theory, ref. [46] suggests strategies for selecting the optimal mix of renewable energy sources to achieve profitability and sustainability objectives.

Then, understanding the diversification benefits associated with these assets is crucial for investors seeking to construct Sustainable ETFs that align with their investment objectives and risk tolerance. By analyzing the performance of different asset classes, investors can make informed decisions about the composition of their Sustainable ETF portfolios.

3.7.2. Cluster 3 Environmental (Light Green)

This cluster delves into environmental considerations within sustainable investing context, particularly concerning SDGs. Ref. [5] examines the potential benefits of incorporating ETFs focused on SDGs into investment portfolios. The research evaluates the performance of SDG-focused ETFs and their impact on portfolio diversification and returns. The findings suggest that investors can benefit from investing in ETFs aligned with companies contributing to SDGs, particularly those focusing on decent work and economic growth. Ref. [47] contributes to the cluster by mapping the Sustainability Accounting Standards Board (SASB) issues to SDGs, providing insights into how companies and investors can align ESG performance with SDGs. The study highlights the importance of considering ESG issues for achieving SDGs and offers guidance for integrating them into investment strategies.

In this way, by examining the performance of ETFs aligned with companies contributing to SDGs, investors can assess the environmental impact of their investment decisions. Mapping SASB issues to SDGs further enhances the integration of environmental factors into investment strategies, thereby promoting sustainability through Sustainable ETFs.

3.7.3. Cluster 8 Renewable Energy (Light Blue)

Finally, Cluster #8 focuses on shifts to renewable energy investments and their implications for portfolio management. Ref. [48] investigates the role of financial capital in facilitating energy transitions towards modern renewable energy sources. The study analyzes data from various countries to understand how financial capital influences the adoption of renewable energy technologies. Ref. [48] finds that financial capital supports transitions to capital-intensive energy types, with implications for both high-income and lower-income countries. Ref. [49] compares healthcare funds and healthcare ETFs in terms of delivering positive alpha, beta, and hedging against market downturn risk. The study provides insights into the effectiveness of different investment vehicles in providing diversification within the healthcare sector and offers practical guidance for investors and financial advisors.

This cluster highlights the importance of renewable energy investments in Sustainable ETFs. Investigating financial capital’s role in supporting energy transitions towards renewable energy sources gives investors insights into the opportunities and challenges associated with renewable energy investments. Additionally, comparing different investment vehicles, such as healthcare funds and ETFs, provides valuable information for investors seeking to incorporate renewable energy assets into their Sustainable ETF portfolios.

3.8. Trending Topics

The analysis presents a thematic map, delineating it into four distinct quadrants highlighted on the density (the degree of development) and centrality (the degree of relevance) of the subjects investigated, as shown in Figure 10. An indispensable focal point emerges that requires a more meticulous and exhaustive examination of the issues located in the upper-right quadrant due to their concentrated relevance and importance [50,51,52].

Figure 10 presents a thematic map that illustrates the trends in research on Sustainable ETFs, dividing them into three principal clusters based on their occurrence and centrality. Each cluster represents a distinct aspect of research on Sustainable ETFs, providing valuable insights into the trends and topics that have garnered attention in this field. By analyzing these clusters, researchers can identify emerging themes and areas for further investigation, ultimately contributing to advancing knowledge and understanding of sustainable finance.

3.8.1. Cluster 1: Risk (Red)

This cluster revolves around keywords related to risk management and analysis in the context of Sustainable ETFs. Keywords such as “corporate social-responsibility”, “financial performance”, and “mutual funds” highlight areas where researchers have explored the risks associated with socially responsible investing and financial performance metrics. The cluster emphasizes the importance of understanding and mitigating risks in Sustainable ETF investments to ensure long-term viability and success.

3.8.2. Cluster 2: Performance (Blue)

This cluster centers on keywords related to the performance evaluation of Sustainable ETFs. Terms like “investment”, “impact”, and “volatility” indicate areas where researchers have examined the financial performance and impact of Sustainable ETFs with different market conditions. In this way, understanding the performance metrics of Sustainable ETFs is crucial for investors and policymakers to make informed decisions about their investment strategies and portfolio allocations.

3.8.3. Cluster 3: Investments (Green)

This cluster focuses on keywords related to investments in Sustainable ETFs and their implications. Keywords such as “financial markets”, “clean energy”, and “governance” highlight areas where researchers have investigated the investment opportunities and challenges associated with Sustainable ETFs. Understanding the dynamics of investments in Sustainable ETFs is essential for investors and policymakers to promote sustainable finance and achieve environmental and social objectives.

4. Discussion

The dynamic growth and development of Green Exchange-Traded Funds (ETFs) reflect their increasing relevance in socially responsible investing (SRI). These instruments have progressed from niche financial tools to central players in aligning sustainability objectives with competitive financial performance. This discussion delves into the evolution of the Green ETF concept, insights into their market impacts and performance, and an analysis of the challenges and opportunities shaping their future. By synthesizing definitions, empirical findings, and theoretical frameworks, the section aims to provide a comprehensive understanding of the strategic importance of Green ETFs in driving innovation, enhancing portfolio performance, and advancing global sustainability objectives.

4.1. Evolution of the Concept of Green ETF

The concept of Green Exchange-Traded Funds (ETFs) has evolved over time, with various definitions emphasizing different aspects of environmental, social, and governance (ESG) criteria.

Table 4. Chronology of evolving definitions for Green ETFs.

Year	Author	Definition
2011	Sabbaghi [4]	Green ETFs are investment vehicles that invest primarily in green stocks, which exhibit positive environmental, social, and governance (ESG) characteristics. They represent diversified portfolios tracking specific green market indices.
2015	Tsolas and Charles [53]	Green ETFs are new investment vehicles combining the diversification benefits of mutual funds with the liquidity of stock securities. They hold primarily stocks exhibiting positive environmental and social governance characteristics, aiming to track specific green market indices.
2022	Naqvi et al. [31]	The study does not provide a specific definition of Green ETFs but assesses the utility of green Exchange-Traded Funds in investors’ portfolios for their dual potential of sustainability and diversification.
2024	Misev and Balles [54]	Green ETFs are defined as those that contain keywords such as “ESG”, “green”, “sustainable”, “ecological”, “eco”, “clean”, “renewable”, “low carbon”, “climate”, “bio”, “ethical”, “responsible”, “recycle”, “solar”, “environment”, “wind”, “progressive energy”, and “SRI” in their asset names.

Source: Compiled from our research utilizing Scopus and WoS datasets.

presents a chronology of definitions from selected studies.

Table 4 serves as a cornerstone for understanding Green ETFs’ conceptual and operational evolution. It synthesizes diverse research contributions to provide a comprehensive framework for exploring innovative and sustainable investment strategies. The progression of Green ETFs, from niche instruments to central tools in addressing environmental and social challenges, underscores their growing importance in financial markets and sustainable finance.

The evolution of Green ETFs reflects a progressive refinement in their definition and conceptualization over time. As RQ1 established, this study highlights how definitions of Green ETFs have shifted, reflecting the academic and practical focus over the years. Ref. [4] initially defined Green ETFs as investment vehicles primarily focused on green stocks, characterized by positive environmental, social, and governance (ESG) attributes, and tracking specific green market indices. This foundational perspective emphasized their role in aligning portfolios with sustainable practices. Ref. [53] built upon this definition, highlighting Green ETFs as innovative financial instruments that combine the diversification benefits of mutual funds with the liquidity of stock securities while maintaining a focus on ESG-aligned investments and green indices [31] shifted the focus from definition to application, evaluating the dual potential of Green ETFs for sustainability and diversification, underscoring their strategic utility in investor portfolios. Most recently, ref. [54] expanded the scope by adopting a keyword-based classification system, identifying Green ETFs through terms like “sustainable”, “clean”, and “renewable”, among others, thereby reflecting the increasing specificity and inclusivity in defining these instruments within the context of sustainable finance.

Additionally, the studies in Table 4 illustrate the multifaceted roles of Green ETFs, highlighting their contribution to market efficiency, diversification, and responsiveness to investor sentiment and external events. Studies like [4,53] emphasize the diversification and risk mitigation benefits of Green ETFs, while research by [54] connects them to behavioral finance and the influence of media-driven investor behavior. Further, as discussed by [31], their alignment with global sustainability goals underscores their potential to generate both financial returns and positive environmental impact.

By capturing this progression, Table 4 highlights the transformative role of Green ETFs and sets the stage for further exploration into their capacity to drive innovation, enhance portfolio performance, and contribute to a more sustainable financial ecosystem.

4.2. Evolving Insights into Sustainable ETFs: Market Impacts, Performance, and Emerging Trends

Studies on ETFs have evolved significantly over recent years, reflecting their growing importance in financial markets and investment portfolios. The key themes include pricing efficiency, tracking ability, impacts on underlying securities, market effects, performance analysis, regulatory frameworks, and investment strategies. These insights directly address RQ3: What thematic areas are observed in the scholarly production of Sustainable ETFs? by identifying the diverse thematic areas shaping the academic discourse on ETFs. Researchers have explored various aspects of Sustainable ETFs, ranging from their historical development and characteristics to their impact on financial markets, investor behavior, and regulatory considerations [55,56,57].

One notable research trend is the increasing attention paid to the performance and effects of Sustainable ETFs on financial markets. Studies have examined liquidity, price discovery, volatility, co-movement of underlying securities, risk–return characteristics, and diversification benefits associated with ETF investments [58,59,60]. Additionally, a growing body of research focuses on specialized ETF categories such as leveraged and inverse ETFs, smart beta ETFs, and foreign-equity ETFs in emerging markets [61,62].

This study also highlights the emergence of new research trends and methodologies in ETF analysis, such as machine learning, artificial intelligence, and the integration of ESG issues into ETF investment strategies [8]. Furthermore, there is a growing emphasis on regulatory frameworks for ETFs, with calls for more comprehensive and unified regulations to address these investment vehicles’ unique characteristics and risks [63].

The literature on Sustainable ETFs has significantly contributed to the evolution of ETF analysis. By focusing on ESG issues, Sustainable ETFs aim to align investors’ financial goals with their ethical and sustainability objectives. Likewise, this study also provides insights into thematic areas such as ESG integration, renewable energy investments, social responsibility, and the impact of sustainable investing on financial performance.

Overall, the literature on ETFs has evolved from initial explorations of their structure and functionality to more sophisticated analyses of their performance, market effects, and regulatory implications. Including Sustainable ETFs in the discourse reflects a broader shift towards responsible investing and sustainability considerations in financial markets.

4.3. Practical Challenges, Future Trends, and Strategic Insights for Green ETF Investments

Green Exchange-Traded Funds (ETFs) have emerged as pivotal tools in socially responsible investing (SRI), seamlessly blending sustainability objectives with financial performance. Recent scholarly works provide a multifaceted perspective on how these instruments are defined, operationalized, and utilized across diverse market contexts. This section explores the practical challenges, future trends, and strategic insights surrounding Green ETFs, offering a comprehensive understanding of their evolving role in the global investment landscape.

4.3.1. Practical Challenges

The studies reviewed highlight several persistent challenges in the adoption and effectiveness of Green ETFs. Regional regulatory inconsistencies emerge as a critical barrier, as noted in research comparing U.S. and European markets [64]. As RQ4 asks, this study highlights the main clusters related to challenges, including regulatory alignment, operational costs, and investor education. These differences impede the creation of standardized frameworks for evaluating ESG performance across regions. Additionally, the high implementation costs associated with integrating technologies like blockchain for carbon validation limit the scalability of Green ETFs [65]. Investor education also remains a challenge, particularly in emerging markets like India, where the awareness of green financial instruments is relatively low [66].

Another issue lies in balancing ethical investment goals with competitive financial performance. While Green ETFs often align with investor values, they may underperform the risk-adjusted returns, as seen in studies comparing green and traditional mutual funds [67]. Moreover, the reliance on narrow inclusion criteria, such as positive screening strategies, can limit diversification and resilience during market crises [35,68].

4.3.2. Future Trends

Technological innovations, investment strategies, and market dynamics shape the future of Green ETFs. As RQ5 was established, this study emphasizes forward-looking trends, such as blockchain verification, crisis-specific ETF models, and developing more inclusive screening criteria. The integration of advanced technologies, such as blockchain for ESG verification, can enhance transparency and attract broader adoption [65]. Expanding the scope of screening strategies to include more diversified and inclusive criteria will be essential for achieving robust long-term performance [35]. Additionally, developing crisis-specific ETF models with customizable resilience features can address the unique challenges posed by market volatility [69].

Emerging markets also present growth opportunities, as demonstrated by India’s efforts to expand its range of green financial instruments [66]. Targeted investor education programs and regulatory support will be pivotal in fostering adoption in these regions. Finally, as the global focus on ESG principles intensifies, a growing need for standardized metrics to consistently measure social and environmental performance across markets is growing [64].

4.3.3. Strategic Insights

Strategically, Green ETFs have proven their resilience and utility as pivotal financial tools for sustainable investing. Ref. [69] demonstrated the ability of Green ETFs to outperform during crises and highlighted their effectiveness as protective mechanisms in volatile markets, offering investors stability and enhanced risk management. This resilience and alignment with global sustainability initiatives underscore their potential to drive positive environmental and social outcomes while maintaining competitive financial returns. As RQ2 established, this study showcases the works of key contributors like [69,70], whose insights have shaped our understanding of Green ETFs.

Insights from energy-focused ETFs [70] and socially responsible investing (SRI) ETFs [71] further emphasize the importance of refining investment frameworks to accommodate evolving market demands and diverse investor preferences. By adapting to these dynamics, Green ETFs enhance their capacity to address both ethical priorities and economic imperatives, fostering a more inclusive and adaptive financial ecosystem. These instruments bridge the gap between sustainability goals and financial growth, reinforcing their strategic value as catalysts for innovation and resilience in the rapidly evolving landscape of sustainable finance.

The discussion has comprehensively explored the evolving role of Green Exchange-Traded Funds (ETFs) in sustainable investing, integrating empirical evidence and theoretical perspectives linked to the RQs, explicitly showing how each question has been addressed. It highlights the multifaceted challenges facing Green ETFs, including regulatory inconsistencies, limited investor education, and the need for technological integration while identifying significant innovation opportunities. By addressing these challenges and leveraging emerging trends—such as advanced screening strategies and blockchain technology—Green ETFs can enhance their impact as financial instruments that align sustainability goals with robust portfolio performance.

Moreover, the strategic insights presented emphasize the transformative potential of Green ETFs to catalyze positive environmental and social outcomes while fostering resilience and growth within financial markets. As tools of both ethical and practical significance, Green ETFs stand at the forefront of innovative investment strategies, reinforcing their pivotal role in advancing the global ESG agenda and shaping a sustainable financial future. This nuanced understanding aligns seamlessly with the study’s objective, offering a clear path forward for stakeholders to maximize the value of Green ETFs in addressing the pressing demands of sustainable finance.

5. Conclusions

This study employs a multifaceted approach utilizing bibliometric and scientometric analyses in conjunction with Bibliometrix, VOSviewer, and CiteSpace tools to comprehensively address each research question and provide a nuanced understanding of the evolving landscape of Sustainable ETF research.

Then, the study effectively addresses several key research questions regarding Sustainable ETF research by thoroughly examining the literature and advanced analytical methodologies. First, it identifies the prominent interest in Sustainable ETF research by conducting a reference analysis, which analyzes the publication years of highly referenced studies. This method provides valuable insights into the temporal evolution of research interest in Sustainable ETFs, allowing for a comprehensive understanding of the field’s development over time; this issue was addressed by answering RQ1.

Second, the study successfully identifies the leading researchers in the Sustainable ETF field by showcasing the top 10 cited studies and their authors. This reference analysis highlights key contributors shaping the discourse, clarifying the individuals and research teams driving innovation and progress in Sustainable ETF research. By answering RQ2, this study offers valuable insights into the intellectual landscape of the field. It acknowledges the significant contributions of influential scholars, such as Maria del Mar Miralles-Quirós, José Luis Miralles-Quirós, Rareş Halbac-Cοtοara-Zamfir, and Maria Eugenia de Boyrie.

Furthermore, the study observes thematic areas in the scholarly production of Sustainable ETFs through keyword analysis. By delineating six distinct clusters covering various aspects such as financial and economic considerations, behavior and governance, risk management, diversification, and social responsibility, by answering RQ3, this study provides a comprehensive overview of the thematic landscape within the field. This approach allows for a nuanced understanding of the multidimensional nature of Sustainable ETFs research and highlights the diverse topics being explored by scholars.

Moreover, this study identified clusters in the Sustainable ETF arena, revealing themes like diversification benefits, environmental considerations, and renewable energy investments. This advanced analytical methodology offers deeper insights into the interconnectedness of research topics and facilitates the identification of core themes driving research in the field. By leveraging bibliometric and scientometric analysis, the study enriches its thematic cluster analysis and enhances the comprehensiveness of its findings; this issue was addressed by answering RQ4.

In order to identify emerging themes experiencing growth in Sustainable ETF research, by answering RQ5, thematic mapping provided valuable insights into the evolving trends and future directions of research in the field, offering researchers and practitioners guidance on areas warranting further exploration and investment.

In conclusion, the study’s multifaceted approach, incorporating reference analysis, keyword analysis, and thematic mapping, enables it to comprehensively address each research question and provide a nuanced understanding of the evolving landscape of Sustainable ETF research. Through these methodologies, the study contributes significantly to advancing knowledge in the field and lays the groundwork for future research endeavors. Lastly, it is important to highlight the emergence of new research trends and methodologies in ETF analysis, such as machine learning, artificial intelligence, and the integration of ESG issues into ETF investment strategies.

However, it is important to acknowledge some limitations of this study. Firstly, the analysis relies heavily on indexed literature, potentially overlooking gray literature that has not yet been widely cited. Additionally, this study primarily focuses on quantitative measures of research impact and thematic analysis, potentially neglecting qualitative aspects of Sustainable ETF research. Further research could address these limitations by incorporating qualitative methodologies, such as interviews or case studies, to provide deeper insights into the dynamics of Sustainable ETF research. Furthermore, considering interdisciplinary perspectives could enrich the understanding of this evolving field. Thus, while this study offers valuable insights and ETFs continue to gain popularity and diversify, further research is needed to comprehensively explore the complexities and nuances of Sustainable ETF research. Hence, further research should explore new dimensions of ETF analysis, regulatory challenges, and innovative investment strategies to meet the evolving needs of investors and markets. The study also highlights potential areas for future exploration, such as how investors incorporate ETFs into portfolio investments, dynamic co-movement analysis, and the application of machine learning in ETF strategy development. Finally, given the breadth of the sustainable finance market and a growing level of awareness by all market players, the authors of this study expect that in the future, all financial mechanisms will be sustainable by default, including ETFs. In this way, sustainable finance will simply be called finance.

The evolving landscape of Green Exchange-Traded Funds (ETFs) highlights their transformative role in sustainable investing, effectively bridging financial performance with environmental, social, and governance (ESG) objectives. This study traces the chronological evolution of Green ETF definitions, from their initial conceptualization as ESG-aligned investment vehicles to their current status as dynamic portfolio diversification and sustainability tools. Early definitions emphasized their focus on green stocks and adherence to ESG principles, while recent perspectives have expanded to include advanced strategies, diversified screening methods, and their alignment with global sustainability initiatives.

Through a synthesis of empirical studies and theoretical insights, this analysis demonstrates how Green ETFs have progressively adapted to address pressing global challenges, navigate shifting market dynamics, and meet evolving investor expectations. These instruments have solidified their position as vehicles for financial growth and as catalysts for advancing sustainability goals, underscoring their critical role in the future of responsible investing.

The examination of practical challenges, such as regulatory inconsistencies, high implementation costs, and limited investor education, underscores the need for more robust frameworks and strategic interventions to foster the adoption of Green ETFs [64]. The results highlight that overcoming these challenges will require regulatory harmonization, broader access to investor education, and adopting technologies like blockchain for ESG verification [65,66]. Meanwhile, integrating advanced technologies, diversified screening strategies, and crisis-specific investment models represents a forward-looking approach to enhancing their utility and resilience [65].

Strategically, Green ETFs offer a unique combination of risk mitigation, market efficiency, and positive social impact, making them indispensable in the transition toward sustainable financial ecosystems. Their demonstrated ability to align ethical investment goals with competitive returns positions them as pivotal instruments in shaping future investment strategies [71]. By addressing the complexities and opportunities associated with Green ETFs, this article provides actionable insights for investors, policymakers, and financial institutions, advancing the discourse on sustainable investing and paving the way for innovative approaches in the ESG landscape.