Last Friday, CBOT soybean futures closed sharply lower, retreating quickly from the three-year high touched earlier in the week. The USDA September supply and demand report was the core bearish driver for the session it raised the U.S. soybean yield estimate by 0.1 bushel to 52.8 bushels per acre and lifted the production estimate by 16 million bushels to a record 4.535 billion bushels, in sharp contrast to widespread expectations of a yield cut, triggering concentrated liquidation of long positions by funds. The core driver behind the sustained rally in U.S. soybeans has been Chinese purchasing. Traders said China bought about 1 million tonnes of U.S. soybeans last week, bringing cumulative purchases to nearly half of the annual 25 million tonne commitment. The USDA confirmed sales of 340,000 tonnes and 272,000 tonnes of new-crop soybeans to China on Wednesday and Thursday, respectively.