Stocks are lower, with the blue-chip Dow losing up to 125 points in trading on Monday and crude oil falling to new lows. Near 12:43 p.m. ET, the Dow was down 123 points, the S&P 500 was down 8 points, and the Nasdaq was down 14 points. It was much uglier in Greece, where the Athens Stock Exchange (ASE) index, which reopened after a five-week closure, fell 23%. Crude oil is sliding to new lows. Brent crude, the international benchmark, fell below $50 per barrel for the first time since January. West Texas Intermediate crude fell below $45 per barrel, the lowest level since mid-March. It's a busy month for US economic data in what's the crucial period before the Fed possibly raises rates in September, as many in the market expect. To start off, we got manufacturing data this morning. The Institue of Supply Management's manufacturing report leaked, coming in at 52.7 for July versus the consensus forecast, June print, and year-to-date high of 53.5. US auto sales crushed it last month. The data is rolling in throughout the day and we're keeping track here. It's been a beat on expectations all around so far. GM sales rose 6.4% (0.4% estimated), and Ford sales jumped 4.9% (1.8) forecast). Twitter shares fell more than 6% to a fresh low of around $28.91.SEE ALSO: IT'S A HUGE WEEK FOR THE US ECONOMY: Here's your complete preview Join the conversation about this story » NOW WATCH: The 13 best features coming to the next iPhone