USDA’s 1 March quarterly stocks and initial planting intentions reports have a history of providing market-moving surprises, and today’s releases add to that history. The corn and soybean stocks had been expected to be record large, and they were. Along with those of wheat, they all exceeded the average trade guesses as reported by newswire services. For corn and soybeans, the difference was substantial at 173 million bushels and 67 million bushels, respectively. Meanwhile, wheat’s stocks were less than 10 million bushels more than expected. By contrast, grain sorghum stocks were considerably smaller than expected, reflecting how tight that balance sheet is becoming.

Stocks of corn and soybeans were surprisingly and bea...