Stocks were sailing along smoothly until about 2 p.m. EST, when an internal memo at Wal-Mart (NYSE:WMT) sent stocks reeling. An email obtained by Bloomberg News quotes Wal-Mart's vice president of finance and logistics as saying, "In case you haven't seen a sales report these days, February MTD sales are a total disaster." That's not exactly a ringing endorsement of consumer spending or Wal-Mart, although the company did say the statements may not be entirely accurate.

The first concern is that consumers have cut back after seeing smaller paychecks in January, affecting spending in late January and now in February. But it does contrast with the University of Michigan-Thomson Reuters consumer sentiment gauge, which rose to 76.3 in February from 73.8 in January. That's the highest reading since November, before taxes went up.

The Wal-Mart leak sent its stock down 2.9% for the day and dragged the Dow Jones Industrial Average (DJINDICES:^DJI) and S&P 500 (SNPINDEX:^GSPC) down 0.25% and 0.33%, respectively. Both indexes had previously been flat for the day.

Friday was also a bad day for commodities. Gold is down 1.9% after the G-20 said it wouldn't punish Japan for making moves to devalue the yen. The group did say it will avoid competitive devaluations from other countries, which put downward pressure on gold because it's seen as a hedge against devaluation.

Oil has suffered a similar fate, falling 1.5% to less than $96 per barrel. This has done little to help oil producers: ExxonMobil (NYSE:XOM) and Chevron (NYSE:CVX) are down 0.7% and 1.1%, respectively. I wouldn't worry too much about the drop in oil, because it's partly a negative reaction to the rise of oil prices in recent months, which may have been overdone.