The USDA unexpectedly raised the U.S. corn yield in the October supply and demand report to a national average of 176.5 bushels per acre, one-half bushel above the average trade guess. This was enough to put yearly production at 15.02 billion bushels, 20 million bushels higher than the September prediction. 

Very few changes were made to corn demand, which put ending stocks at 1.5 billion bushels, up 100 million bushels from September. This is a 10.1% stocks-to-use and requires less...