The seesaw battle between bulls and bears continued today as stock markets moved lower in late trading. As I'm writing, the Dow Jones Industrial Average (DJINDICES:^DJI) is down 0.49%, and the S&P 500 (SNPINDEX:^GSPC) has fallen 0.24%.

Yesterday, markets rose on improved manufacturing data, and today markets are moving lower as investors worry about earnings and Spain's bailout. There's some uncertainty over when Spain will ask for a bailout, and Reuters reported that Germany was asking the country to hold off for the time being. Banking stocks in particular have been on wild swings as Europe's leaders battle over bailout details and timelines, and I wouldn't expect the rollercoaster to stop anytime soon.

McDonalds (NYSE:MCD) was one of the Dow's big losers today, falling 1.2% a day after analysts at Janney Capital downgraded the stock to neutral. The analysts are worried about the pace of same-store sales growth, and this plays right into concerns about third-quarter earnings today.

DuPont (NYSE:DD) fell 1.9% today, leading the Dow lower after Wells Fargo reduced estimates for the company. The analyst pointed to Performance Coatings' discontinued operations and general macroeconomic concerns as the reason for the change.

Earnings season begins next, and Alcoa (NYSE:AA) will kick things off on Tuesday. The market is beginning to have real concern that earnings will be disappointing, so investors should keep an eye on how companies are performing. Confidence has begun to rise, but it may not be enough to save a disappointing third quarter.

Fool contributor Travis Hoium does not have a position in any company mentioned. You can follow Travis on Twitter at @FlushDrawFool, check out his personal stock holdings or follow his CAPS picks at TMFFlushDraw.

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