Grain and soy prices posted modest gains during the overnight session. They were led again by wheat, which followed up on Wednesday’s big rally. The volatile Euronext wheat futures also surged ahead, adding to yesterday’s big move. As CME day session trading resumed, however, the Euronext market turned and began a sharp retreat. Its December contract traded as high as 208.25 euros, up 5 euros from yesterday, but then turned south to a close of 201.75, down 1.50 euros. U.S. wheat futures basically followed that same higher-lower pattern today. KC December was up 8.5 cents at its high for the day but closed down 8.25 cents, and Chicago December posted an early gain of 7.75 cents before sliding back into the red to close 6.75 cents...