Can Soybean Tariff Shocks Trigger Abnormal Asymmetric Phenomena in Futures Markets? Evidence from the 2025 U.S.–China Trade Friction

This study, set against the backdrop of escalating trade tensions between China and the United States, examines the impact of soybean tariff adjustments on the abnormal asymmetric behavior in the futures market. By employing specialized analytical methods that capture market volatility asymmetry and event study techniques, we focus on the multi-stage soybean tariff adjustments to analyze their effects on market return transmission, volatility asymmetry, and market stability. This study compares the market responses to positive and negative shocks and the distinct performances of the futures markets in China and the United States, with the core aim of verifying whether soybean tariff shocks trigger abnormal asymmetric behavior in the futures market. The results show that tariff shocks significantly lead to asymmetric characteristics in market volatility, with negative shocks having a more pronounced impact on market volatility than positive ones. During the trading days before and after the announcement of tariff policies, the cumulative abnormal return difference, which measures the disparity in market reactions to related assets, also rose significantly. This indicates that tariff adjustments are the core factor causing abnormal asymmetric phenomena in the market, and the commodity futures market needs to pay attention to such asymmetric risks triggered by policies. The value of this study lies in its targeted analysis of the dynamic impact of tariff shocks, combined with volatility analysis and event study methods, to quantify the asymmetric effects in cross-border markets. The research conclusions can help investors avoid risks related to trade policies and provide references for policymakers to stabilize fluctuations in the commodity market, ultimately facilitating the market’s more efficient response to trade policy shocks and reducing information asymmetry in futures market pricing.