NEW YORK ( TheStreet) -- The post QE3/poor earnings season sell-off is suddenly getting serious. Tuesday's steep drop marked the first time the Dow Jones Industrial Average booked two 200-point-plus declines within three sessions since late November 2011, and what's probably most concerning is that it was a messy pullback. The lack of a distinct catalyst implies an element of panic is creeping in. Without much economic data to go on this week, there's really only been earnings to point to as far as U.S. corporate news goes, and as expected, earnings have been fairly shoddy. According to the latest Thomson Reuters data, 57.2% of S&P 500 companies have topped analyst profit expectations and just 37.2% have beaten the consensus revenue view vs. respective averages of 67% and 55% over the past four quarters. But that's not a surprise and it's still based on a relatively small sample size with just 29% of the S&P 500 having reported. Not exactly an overriding reason to run for the exits. At least not yet. The blended estimate, combining analyst views and reported results, is pointing to a year-over-year decline of 2.4% in third-quarter results, just a bit worse than the 2.1% drop seen on Oct. 1. Again, not good but not unexpected. So that leaves the difficult task of quantifying the other simmering issues out there. Wall Street loathes uncertainty and that means the intervening weeks between now and the presidential election could be particularly rocky. Some of the sub-text of Tuesday's equity exodus was that Mitt Romney held his own in Monday night's debate with President Barack Obama, tightening up an already close race even further. That leads to discussion about what a Romney victory means for Ben Bernanke's future with the Federal Reserve and on and on it goes. The political intrigue just adds to the growing fears about the fiscal cliff, the other big but vague hurdle that investors need to clear in order to be bullishness about the end of 2012. Who's confident that Washington, D.C. will be able to pivot quickly in the aftermath of a contentious election season? A show of hands? The other big question mark is when and if Spain will ask for a bailout. As with everything with Europe these past few years, the progress is painstakingly slow and the headlines never really deliver much satisfaction. It all adds up a messy pullback that's as difficult to explain as it is to explain away. And that in and of itself may be reason enough for many to take some profits.