http://www.nytimes.com/2015/06/30/business/international/daily-stock-market-activity.html?_r=0

“But the real test will come on Tuesday when the I.M.F. payment comes due.”

If Greece fails to make payment, Mr. Weinberg said, the country could be declared either in arrears or in default, with such a determination taking several days. If Greece is declared in default, “a clock starts for creditors to deal with it, and just the existence of that uncertainty will be a cloud over the market, because we won’t know for a while,” he said.