The longest run for the S&P 500 Index (SNPINDEX:^GSPC) in nearly a decade came to a close on Monday, as the index finally fell after an eight-day run. Three S&P companies in particular caught the brunt of the damage to start the week off.

Shares in online movie streaming company Netflix (NASDAQ:NFLX) followed the same pattern as the broader market today: Shares fell 4.4% after a stunning run-up in the stock in the past week. Granted, Netflix's rise was a little more abrupt than the market's; shares have surged more than 63% in the past five trading days alone. The company reported stunning growth in its subscriber base for the quarter, sparking a flurry of buying last week. Today's sell-off reflects some understandable profit-taking from the recent red-hot rally.

Today's second-largest decliner, defense company Lockheed Martin (NYSE:LMT), saw shares fall 3.3% as investors worried about a possible repeat of the hellish situation rival Boeing has gone through in the New Year. A pilot aborted a recent test run in the F-35B airplane because of issues with the propulsion system. Thankfully for Lockheed, the system is made by a unit of United Technologies. Still the 2001 Pentagon contract to provide more than 2,400 F-35s was with Lockheed, so the company does bear some responsibility. Today's sell-off drove the stock's dividend yield to a highly respectable 5%. 

The last of the day's underperformers was United States Steel (NYSE:X), which also lost 3.3% Monday. The fall may have simply been due to a downgrade of one of its main competitors, AK Steel, by investment bank Goldman Sachs. With earnings due tomorrow before the bell, you can't blame Wall Street for getting a little spooked by the 7.4% decline in another steel giant's shares.

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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