A Congressional Research Service insight summarizes the WTO cases the U.S. brought against China's farm support policies for wheat, rice and corn. China notified the WTO on June 18, 2020 that it had changed its rice and wheat policies, and the cases have been sent to arbitration.
Subsidy changes that reduce Chinese support for domestic wheat, rice and corn could shift import needs over time. The dispute mainly matters as background for trade-policy risk.
After 137 past neutral policy events, Wheat (SRW) moved a median -0.4% over 5 sessions (43% higher; middle half -1.9% to +1.2%), and +0.3% over 20.
After 439 past neutral policy events, Corn moved a median +0.1% over 5 sessions (51% higher; middle half -1.3% to +1.2%), and +1.1% over 20.
After 100 past neutral policy events, Rough Rice moved a median +0.0% over 5 sessions (51% higher; middle half -2.6% to +2.3%), and +0.7% over 20.
Moves of each commodity's benchmark from the last close before the event. Historical reads pool past events of the same kind; they describe what happened, not what will. Not investment advice.