GBP/USD rose to around 1.4220 on January 31, 2018, its best level since the previous Friday, before easing as the dollar steadied after the FOMC statement. UK Prime Minister May said in Beijing she would deepen trade ties with China, while European Commission officials reportedly rejected the City of London's proposal for a post-Brexit financial services deal.
The report notes that the EU has tied a better trade deal to acceptance of the four freedoms of the Single Market.
Currency swings tied to the Fed and Brexit talks change the dollar cost of imported feed for UK and European buyers. The grain market impact is minor.
Not enough comparable past events yet for a historical read.
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.