Stocks opened higher to start the month after a close in the red on Friday, but slid in early trading. Near 10:17 a.m. ET, the Dow was down 5 points, the S&P 500 was down 2 points, and the Nasdaq was down 15 points. Treasuries sold off after the data, with the yield on the benchmark 10-year note jumping as much as five basis points, or 0.05, to 2.15%. In economic data, the Purchasing Manager's Index reading from Markit came in at 54.0 in May, falling from the previous month but beating forecasts. The ISM Manufacturing index rose in May, at 52.8, beating expectations for 52.0. Personal income rose more than expected in April, spending was flat, and inflation rose less than expected. Personal income climbed 0.4% (versus 0.3% expected), spending was unchanged (versus 0.2% expected). "Core PCE," the Fed's preferred measure of inflation, rose 0.1% month-over-month and 1.2% year-over-year. And, construction spending rose 2.2% in April, better than forecasts for a 0.7% gain. We got a $16.7 billion merger to start the week. Intel is buying Altera for $54 a share in an all-cash deal that had been rejected. In morning trading, shares of Altera were up as much as 6%, while shares of the world's largest chipmaker were down about 2%. Markets will be paying attention to Greece this week. On Sunday, the Greek government said an agreement with creditors could be reached by tomorrow. Meanwhile, the next debt repayment to the International Monetary Fund is due on Friday; Greece pulled cash from its reserves to make the last payment.SEE ALSO: Goldman Sachs calls record stock buybacks a 'questionable use of cash' Join the conversation about this story » NOW WATCH: Here's how Floyd Mayweather spends his millions