S&P 500 struggling to hold Friday's low

S&P 500 at the lows of the week but Friday's low holding so far

Worries about Greece are hitting the stock market. The feeling that a deal was a near-certainty has slipped away as significant gaps remain and sides appear to be digging in their heels.

Watch for stops on a break. Could be an ugly close if it breaks and that will add to the bid in the yen.