Yesterday's stock market optimism proved short-lived, as markets around the world are falling as the European crisis appears to be spreading inexorably into the Spanish economy. While Greece has attracted a lot of attention, Spain is a much larger part of Europe's overall economic activity, and so its problems indicate a significant escalation of the crisis. As a result, the Dow Jones Industrials (INDEX: ^DJI) quickly fell more than 1% in the first hour of trading and were down about 150 points at 10:45 a.m. EDT.

Banks are taking it on the chin, with both Bank of America (NYSE: BAC) and JPMorgan Chase (NYSE: JPM) falling around 1.5%. Interest rates on U.S. Treasury bonds dropped to record lows, with the 10-year yield (INDEX: ^TNX) dropping to 1.65%. Although many banks own massive portfolios of Treasuries, they also stand to lose as the yield curve becomes less steep. Moreover, even though B of A and JPMorgan argue they have minimal European exposure, they would still be on the front lines if the situation escalated into a global financial-system event.

Beyond the Dow, though, Facebook (Nasdaq: FB) is finally posting a modest gain after several days of losses took it down almost 25% from its $38-per-share offering price. As traders are still getting used to how the stock behaves, it's hard to pin the gain on any news having to do with the company's fundamentals. Moreover, you shouldn't conclude that such a modest gain indicates that Facebook has hit bottom, as many influential analysts believe the stock could drop further from here. Yet options now available on the stock show a predominance of bearish bets, suggesting that Facebook shares could eventually find a floor -- if contrarian thinking proves correct.

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