Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

The euphoria stemming from the Federal Reserve's decision not to taper its monthly asset-buying program yesterday wore off pretty quickly. Wall Street digested the news, bid stocks higher, and promptly sold off, all in a 24-hour window. Today, the S&P 500 Index (SNPINDEX:^GSPC) dropped 3 points, or 0.2%, ending at 1,722. While the decline was by no means severe, three S&P components experienced sudden pullbacks as a direct result of the Fed's decision yesterday.

Regions Financial (NYSE:RF) shed 4.2%, ending as one of the most severe decliners in the entire 500-stock index. As its name suggests, Regions is a regional bank, and regional banks had a rough go of it on Thursday. These smaller commercial banks make their money on the spread -- the difference between what they pay for deposits and what they charge to lend money. The Fed essentially said that interest rates would remain low for the foreseeable future, putting a strain on the earnings prospects for Regions. 

KeyCorp (NYSE:KEY) shares lost 3.9% as Wall Street went through a similar line of thinking with the money center bank. The Cleveland-based bank can look forward to an unknown amount of time where its margins won't be going much higher, a prospect that had driven shares of KeyCorp up 37% in 2013. Now investors have to swallow their pride and wait until the next Fed meeting for any changes in the stimulus program. 

Lastly, Newmont Mining (NYSE:NEM) dropped 3.5%. The company, which primarily mines for gold and copper, jumped an impressive 8.2% yesterday on the Fed announcement, which would send the price of gold up more than 4%. The precious metal's largest single-day gain since 2009 was a godsend for Newmont yesterday, but investors pared back their optimism on Thursday, acknowledging that the 8% jump might have been a little extreme. 

Fool contributor John Divine has no position in any stocks mentioned. You can follow him on Twitter @divinebizkid and on Motley Fool CAPS @TMFDivine.

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