Grain prices closed mixed today, with corn closing almost at its settlement price for yesterday, while soybeans closed near its lock limit down price, and wheat closed up for the day. The gradual downward slope of corn and soybean prices during the first half was difficult to trade early in the day, but profitable. Wheat continues to be the most volatile of grains, with recent margin changes reflecting the tremendous volatility. The wheat margin is now more than double the margin of soybeans. It may perhaps be more profitable for traders to leave wheat alone, and trade soybeans instead.