Econ Papers Daily / 期刊论文
当贸易政策冲击触及谷底：2025年大豆期货市场中的定价、波动与投机
When Trade Policy Shocks Hit the Pit: Pricing, Volatility and Speculation in the 2025 Soybean Futures Market
摘要
This paper explores responses to major trade policy shocks in the soybean futures market in 2025. Using an event‐study framework, we analyse short‐run movements in soybean futures prices, historical volatility, implied volatility and speculative positioning around three major policy shocks: the U.S. tariff announcement targeting China on February 1, the reciprocal tariff announcement on April 2, and Argentina's temporary suspension of soybean export taxes on September 22. Broader in scope, the April reciprocal tariff package was associated with the clearest and strongest response. Futures prices fell by about 6% within two trading days, while implied volatility rose sharply. Following the February announcement, implied volatility increased immediately and then receded, while downward repricing became evident only after China's retaliatory tariffs took effect, suggesting that uncertainty rose before the implications for U.S. export demand became clearer. Argentina's export‐tax suspension, by contrast, was followed by limited repricing, a later decline in implied volatility, and greater speculative positioning relative to commercial hedging needs. The cross‐event comparison suggests that the timing and composition of market adjustment vary with the scope, directness and subsequent evolution of each policy episode.
中文摘要
本文探讨了2025年大豆期货市场对重大贸易政策冲击的反应。我们采用事件研究框架，分析了围绕三次重大政策冲击——2月1日美国宣布针对中国的关税、4月2日宣布的对等关税，以及9月22日阿根廷暂时取消大豆出口税——大豆期货价格、历史波动率、隐含波动率和投机持仓的短期变动。就影响范围而言，4月对等关税一揽子措施与最清晰、最强烈的市场反应相关。期货价格在两个交易日内下跌约6%，隐含波动率大幅上升。2月公告发布后，隐含波动率立即上升，随后回落，而向下重新定价直到中国报复性关税生效后才变得明显，这表明不确定性在美国出口需求所受影响变得更加清晰之前已经上升。相比之下，阿根廷暂停出口税之后重新定价有限，隐含波动率较晚下降，且相对于商业套保需求而言投机持仓增加。跨事件比较表明，市场调整的时机和构成因每一政策事件的范围、直接性及后续演变而有所不同。