December Corn futures closed marginally lower on Thursday, recovering from early session weakness to post the third-highest close for the contract. The market is digesting the largest August monthly rally in over 50 years, driven by late-season growing concerns and expectations of lower yield estimates. Traders are now looking ahead to next week's USDA report, anticipating reduced production forecasts following disappointing crop tours. In the cash market, weekly export sales were skewed by the marketing year rollover, with old crop sales showing negative 830,000 metric tons against strong new crop sales of 1.98 million metric tons. Ted Seifried of Zaner Ag Hedge breaks down the historic rally and shifting supply fundamentals.