WHAT HAPPENED: The biggest down day for stocks in three months.
BY THE NUMBERS: Of 30 Dow stocks, 29 declined. All 10 sectors of the S&P 500 declined. Dropping stocks outnumbered those that advanced by 10-to-1.
WHAT'S NEXT: Thursday is an important deadline as Greece seeks its next bailout. And Friday brings a closely watched update to the U.S. unemployment rate.