1. Introduction
The study of commodity market dynamics has been a cornerstone of financial research, offering valuable perspectives on price formation, risk management, and market efficiency. The global economy relies heavily on commodities, particularly the oil and natural gas sector, as well as other important commodities such as energy, agriculture, minerals, and metals. Among the range of commodities, orange juice futures (OJ = F) have been a particularly interesting area of study already for several decades (
Roll 1984) due to their distinctive market traits and the significant impact of both natural and economic factors. In addition, evaluating orange juice prices is crucial because several interrelated factors significantly impact the global market and consumer behavior (
Wang and Wei 2021;
Zhang et al. 2018).
Is it possible to reliably predict commodity prices? This question has been the subject of ongoing discussion in the financial and economic literature. For example, the recent surge in orange juice prices can be attributed to extreme weather events and persistent diseases affecting major orange-producing regions, i.e., hurricanes and pest infestations (
Durbin and Pollastri 2024). Weather greatly influences orange juice production, unlike other widely produced commodities. Nevertheless, commodity prices are generally considered more unpredictable than stock prices or exchange rates, posing challenges for accurate forecasting. Factors like the interaction of demand and supply, economic expansion, market predictions, government regulations, and unexpected events such as spillover effects, pandemics, war, and global debt crises all have an impact on commodity futures prices (
Zhao et al. 2016). These complex factors are the primary drivers of the significant price fluctuations in the spot market prices of commodities. As a result, the expectation is that predicting commodity price trends, specifically, in this case, the orange juice futures prices, will not only help mitigate volatility and reduce risk in commodity markets but can also support governmental entities in making sound and long-term economic choices. Therefore, the motivation for this research is tied to the unique characteristics of the orange juice futures market, which is heavily influenced by various factors that create challenges for traders and investors. The study highlights the need to develop robust forecasting models to improve investment outcomes and reduce market risks, especially given the significant volatility of orange juice futures prices compared to other commodities like gold or oil.
Given the latest technological advancements, various methods are being utilized to forecast prices in the financial industry (
Ampountolas 2023;
Gupta and Nigam 2020). Although traditional econometric techniques, for example, the vector autoregressive model (VAR) struggle to accurately predict the non-linear aspects of commodity prices due to their robust linear assumptions (
Sun et al. 2022;
Wang and Fang 2022), advanced models such as machine learning techniques have gained significant attention due to their ability to observe volatility characteristics, non-linear information, and historical data effectively (
Ampountolas 2024;
Butler et al. 2021;
Zhao et al. 2017) or combining models (
Barrow and Crone 2016). Therefore, in the financial and economics literature, we have encountered many authors since the early years, for example,
Kroner et al. (
1995) who employed machine learning techniques, such as the Support Vector Regression (SVR), Long Short-Term Memory (LSTM), Recurrent Neural Networks (RNNs), Multi-Layer Perceptron (MLP), convolutional neural networks (CNNs), gate recurrent units (GRUs), backpropagation (BPNN) models, and many other models to validate the impact of various factors on predicting commodity futures prices.
Limited literature examines the price forecasts of orange juice futures (OJ = F) as an independent asset. Most research focuses on commodities like gold or oil, with many papers examining multiple commodities inclusively. Motivated by this and the enormous price growth during the last two years, we examine various forecasting models—ARIMA, LSTM, RNN, BPNN, SVR, NAR, and ConvLSTM—to predict commodity futures market’s prices of orange juice futures prices. We also include other factors such as commodity futures (ES = F) and S&P500 Indexes. Therefore, we employ two forecasting horizons: 5 trading days and 10 trading days. Thus, this study aims to contribute to current research by analyzing and predicting the price trends of orange juice futures in the selected commodity markets. Additionally, we present a comparative analysis of the forecasting models based on loss functions and performance metrics. As such, predicting orange juice futures prices is essential because this market is highly volatile and affected by a range of unpredictable factors that have significant economic impacts. Accurate predictions can help stakeholders mitigate volatility, manage risk, and make more informed decisions in the commodity market. Moreover, given the increasing price volatility in recent years, enhanced forecasting methods can improve profitability for stakeholders involved in futures trading.
Our results revealed that for both the 5-day and 10-day horizons, advanced neural network models, particularly LSTM and ConvLSTM, consistently outperformed the other forecasting models. These models achieved the lowest error rates and demonstrated superior capability in capturing temporal dependencies, with ConvLSTM also effectively modeling spatial and temporal data patterns. The directional accuracy and
Diebold and Mariano (
1995) test supported the findings. In the 10-day horizon, the LSTM and ConvLSTM models again showed significantly lower errors and better alignment with actual values than ARIMA, which had the highest error rates. The BPNN model performed well when all factors were included, and the SVR model maintained consistent accuracy, especially for single-factor predictions. The DM test indicated significant differences in forecasting accuracy, favoring advanced neural network models.
Section 2 briefly overviews the current literature, and
Section 3 discusses the relevant forecasting models and performance assessment metrics and details the data.
Section 4 then presents an analysis of the empirical study’s findings.
Section 5 summarizes the study’s conclusions and outlines potential directions for future research.
2. Literature Review
In one of the earliest studies,
Roll (
1984) confirmed that the weather condition variable impacts the market for frozen concentrated juice. Orange juice prices are impacted by high volatility as a result of concerns about extreme weather events that could affect production. However, he demonstrated that weather accounts for only a small portion of the fluctuations seen in futures prices. In another work,
Kroner et al. (
1995) utilized time-series approaches to generate long-term predictions of commodity price volatility by integrating investors’ anticipated volatility. The authors assessed various forecasts of commodity price volatility, categorizing them into three groups: (1) forecasts based solely on expectations derived from options prices, (2) forecasts relying exclusively on time-series modeling, and (3) forecasts that combine market expectations and time-series techniques. They concluded that the forecasts proposed in category (3) outperformed the other two categories.
Brooks et al. (
2013) analyzed whether there is consistency in the evidence supporting two theories on commodity future pricing over time. The authors explored if the ability of commodity futures to predict prices is related to their seasonal fluctuations, and they also examined if there are changes in the pricing relationships at different times. They found more compelling evidence of seasonal patterns in the basis, which aligns with the storage theory. The findings reveal that structural changes mainly involve adjustments in the starting points rather than the trends, indicating that the predictive power of the basis remains consistent across various economic conditions. The study by
Black et al. (
2014) investigates how stock and commodity prices are related and whether this connection can be utilized to predict stock returns. Since both prices are associated with anticipated future economic performance, they are expected to have a lasting relationship, while shifts in sentiment toward commodity investments may impact how the response to imbalances occurs. The findings indicated that there is a long-term relationship between stock and commodity prices, and further tests identify disruptions in the predictive regression. The paper by
Atsalakis et al. (
2016) introduces an innovative method for predicting the price direction of 25 commodities on the global market using a neuro-fuzzy controller. The prediction system utilizes two adaptive neural fuzzy inference systems (ANFISs) to create an inverse controller for each commodity. The findings demonstrate a 68.33% hit rate with a significant improvement in return on equity compared to the buy-and-hold strategy.
In addition to traditional econometric approaches, various machine learning techniques are used to uncover the inherent complexity of commodity prices. The most common machine learning methods include neural networks (NN) and support vector machines (SVM), which are favored for their ability to model intricate characteristics like nonlinearity and volatility. Hybrid models have also demonstrated superior forecasting accuracy compared to their machine learning models.
Drachal and Pawłowski (
2021) briefly overviews how genetic algorithms (GA) are used to predict commodity prices. The authors concentrated on a hybrid method (i.e., combining genetic algorithms with other approaches) used in situations like determining if a complete forecasting technique can be split into two or more distinct parts, with one part being based on a GA and the other parts based on different methods. Another study by
Jiang et al. (
2022) utilized various machine learning techniques to confirm the influence of investor sentiment on estimating the price of crude oil futures. The authors included several forecasting models, such as the MLP, LSTM, SVR, RNN, and GRU models. The results indicated that the Long Short-Term Memory model yielded the best results when combined with the composite sentiment index. This was attributed to a reduced rate of accuracy errors and improved directional accuracy when forecasting next-day-ahead prices for time-series analysis. In a similar study,
Guo et al. (
2023) utilized machine learning to analyze historical data, volatility, and non-linear characteristics. They assessed the predictive capabilities of neural network models such as the GRU, MLP, LSTM, RNN, CNN, SVR, and BPNN models on crude oil futures. The set of assessment tests illustrated that the GRU model surpassed other models in terms of accuracy and performance when forecasting crude oil futures prices. Moreover, the incorporation of relevant factors resulted in enhanced forecast accuracy for the proposed models. A recent study by
Zheng et al. (
2024) reported the effectiveness of hybrid models in enhancing the accuracy of crude oil price forecasts when compared to single models. Their research introduces an innovative interval-based approach. Initially, they apply variational mode decomposition (VMD) to split the original training series into low- and high-frequency components. The low-frequency component is considered an inseparable random set. It is forecasted using a newly developed autoregressive conditional interval (ACI) model, while the high-frequency component is predicted using interval Long Short-Term Memory (iLSTM) networks. The final interval-valued prediction is obtained by combining the forecasts of both components. Additionally, the study designs and implements a daily trading strategy based on interval-valued data.
Ren et al. (
2024) introduced an innovative imaging technique to predict the daily price data of crude oil futures. Utilizing convolutional neural networks (CNNs), they achieved higher accuracy in predicting future price trends than other standard forecasting methods. The findings indicate that images can capture more nonlinear information, which is advantageous for energy price prediction, particularly during significant fluctuations in crude oil prices. In a different study,
Ampountolas (
2024) studied GARCH models and the Support Vector Regression (SVR) model to understand better how volatility changes in commodity returns, like gold and cocoa, as well as the financial market index S&P500. The evaluation showed that Support Vector Regression (SVR) performs better than traditional GARCH models for short-term forecasting, suggesting it could be a valuable alternative for predicting financial market trends. These results highlight the importance of choosing the right modeling techniques for specific types of assets and forecasting time frames.
In conclusion, an extensive body of literature discusses predicting volatility in commodity futures markets, mainly for energy, crude oil, or metals. Throughout the years, forecasting techniques have progressed from traditional econometric approaches to innovative machine learning methods. Consequently, the accuracy of forecast models is gradually increasing, and at the same time, it has been demonstrated that the variables influencing the prediction of commodity futures prices are varied.
5. Conclusions
This study evaluated the forecasting accuracy of various models with different configurations over 5-day and 10-day trading horizons to forecast orange juice futures (OJ = F) prices. We have employed a dataset from July 2022 to June 2024. Our analysis included traditional models like ARIMA and advanced neural network models such as LSTM, RNN, BPNN, SVR, and ConvLSTM, with varying influencing factors like the Commodities Index and the S&P500 Index. In addition, we have adopted a set of loss function metrics to evaluate the accuracy of each model and various tests to assess the performance of each forecasting model.
For the 5-trading day forecasting horizon, the advanced neural network models, particularly LSTM and ConvLSTM, consistently outperformed traditional models like ARIMA. LSTM achieved the lowest error rates and demonstrated superior capability in capturing temporal dependencies, especially in single-factor and S&P500 Index predictions. ConvLSTM also exhibited strong performance, highlighting its effectiveness in modeling spatial and temporal data patterns. The directional accuracy and Diebold–Mariano test further supported the superiority of LSTM and ConvLSTM over other models.
In the 10-trading day forecasting period, we observed similar trends. While ARIMA displayed the highest error rates, the LSTM and ConvLSTM models showed significantly lower errors and better alignment with actual values. The BPNN model also performed well, mainly when we incorporated all factors. The SVR model maintained consistent accuracy across datasets, especially for single-factor predictions. The Diebold–Mariano test results indicated significant differences in forecasting accuracy, with advanced neural network models generally outperforming traditional models.
The findings of this study demonstrate that advanced models such as LSTM and ConvLSTM outperform traditional methods like ARIMA in forecasting orange juice futures prices. Specifically, LSTM achieved the lowest error rates across various factors, including the Commodities Index and S&P500 Index. This differs from previous research on commodities such as crude oil and gold, which favored machine learning techniques (e.g., LSTM, GRU) while emphasizing different influencing factors such as investor sentiment and macroeconomic indicators. For example, research by
Guo et al. (
2023) highlighted the superior performance of GRU in crude oil forecasting, particularly when considering relevant factors like volatility and historical data. Furthermore, while previous studies applied hybrid models to energy commodities, this study demonstrates the advantage of neural network models for commodity markets, emphasizing the need to customize forecasting tools to the distinctive characteristics of each market.
Our empirical results also have practical implications. Therefore, investors and analysts can promptly analyze market trends and identify potential risks based on the forecasting model results. As we have observed, the findings emphasize the superiority of advanced neural network models, particularly LSTM and ConvLSTM, in forecasting complex time series data. These models effectively capture underlying patterns and trends, offering enhanced forecasting capabilities compared to traditional models like ARIMA. Incorporating influencing factors further improves the predictive performance of these models, underscoring the importance of considering multiple variables in the forecasting of financial assets. This optimization enhances investors’ investment performance and reduces risk. Therefore, the DM test in both periods supports the above findings by indicating that models like LSTM and ConvLSTM not only provide statistically better predictions but also can offer traders and investors more reliable forecasts for decision-making. This could lead to improved returns and reduced risks, especially in volatile markets such as orange juice futures.
Limitations and Further Research
Despite the promising results, this study, like any other, has limitations that warrant further research. First, the dataset was limited to specific financial indices and assets. As such, future research could explore a broader range of variables and datasets to enhance the generalizability of the findings. In addition, we observed only two forecasting horizons (5-trading day and 10-trading day steps). Examining shorter- or longer-term forecasting estimations could provide more insights into the robustness and reliability of these models.
Second, while advanced neural network models showed superior performance, model optimization is also very important. Future studies should explore different optimization methods to enhance forecasting accuracy or incorporate additional forecasting models, such as hybrid models and parameters. At the same time, although neural networks like LSTM and ConvLSTM can effectively model nonlinear relationships, they require extensive data for training to avoid overfitting, especially in highly volatile markets like orange juice futures. Additionally, neural networks are computationally intensive, requiring significant time and resources for both training and fine-tuning, particularly as the complexity of the network increases. Finally, another practical consideration is the interpretability of these models. Neural networks are often seen as black boxes, making it difficult for users to understand how predictions are derived.
Finally, the study primarily focused on point forecasts. Introducing probabilistic forecasting methods could offer a more comprehensive evaluation of model performance by considering uncertainty and confidence intervals in predictions. Furthermore, the economic implications of these forecasts were not analyzed. Future research should assess the practical applications and financial benefits of employing advanced neural network models for trading and investment strategies.
Nevertheless, the study demonstrated the potential of the models utilized in financial forecasting, and further research could lead to even more robust and practical forecasting solutions.