Much like yesterday, Tuesday's CME Group grain and soybean markets will start sharply lower.

The Early Calls for the commodities are 7-10 cents lower for corn, 10-12 lower on soybeans, and 8-10 cents lower for wheat.

Greece's admission of missed deficit reduction targets sent the Dow Jones Industrial Average stocks plunging, to start the fourth quarter Monday. Those worries continue today. 

In overnight electronic trading, the Dec. corn futures contract traded 9 1/2 cents lower at $5.83 per bushel. The Nov. soybean futures contract traded 10 1/4 cents lower at $11.67 1/4 per bushel. The Dec. wheat futures contract traded 9 1/2 cents lower at $6.10. For Dec. soymeal futures, the contract traded $1.90 per short ton lower at $305.10 and Dec. soyoil $0.50 lower at $49.50. 

The outside markets are not supportive for Tuesday's grain trade. The real factors driving the calls are the sharply lower overnight markets.