Stocks sold off sharply Friday, with the Dow erasing all of its gains since the Fed announcement, as uncertainty over the central bank's bond-buying program spooked Wall Street.
Volatility was amplified as Friday also marked the "quadruple witching," when stock index futures, stock index options, stock options and single stock futures all expire. This event takes place four times a year on the third Friday of March, June, September and December.
Still, all three major averages finished in the black for the third-straight week.
"We initially had the kneejerk reaction after the Fed announcement, and now the psychology's shifted to 'what's next'—we have a very busy economic calendar next week and now that we're data-dependent, that's going to be important," said Art Hogan, managing director at Lazard Capital Markets.
The Dow Jones Industrial Average plunged more than 180 points, dragged by Caterpillar and Microsoft. The blue-chip index set an all-time high on Wednesday and is still posted a gain for the third-straight week.
The and the Nasdaq also closed sharply lower.
The CBOE Volatility Index (VIX), widely considered the best gauge of fear in the market, ended above 13.
For the week, the Dow rose 0.49 percent, the S&P 500 rallied 1.30 percent and the Nasdaq jumped 1.41 percent. Boeing led the weekly Dow gainers, while UnitedHealth slumped.
After the market close, Dow components Alcoa, Bank of America and Hewlett-Packard will be replaced by Goldman Sachs,Nike and Visa. The change marks the first new names for the blue-chip index in nearly two years.
All key S&P sectors ended higher for the week, led by industrials and utilities.
Meanwhile, BlackBerry plunged nearly 20 percent after the troubled smartphone maker announced preliminary second-quarter results that disappointed current estimates. In addition, the company said it will slash approximately 4,500 jobs, or nearly 40 percent of its workforce, as part of its massive restructuring plan.
Stocks opened lower after St. Louis Federal Reserve Bank President James Bullard said the central bank could start winding down its $85-billion monthly bond purchase program during its October meeting.
"This was a close decision here in September," Bullard said in an interview with Bloomberg, emphasizing the role that economic data has played and will continue to play in Fed decisions.
The dollar rose to a one-week high against the yen following his comments.
Separately, Bullard said low readings on inflation means that the Fed can be patient on deciding when to scale back its pace of asset purchases.
"While I expect inflation to rise during the coming quarters, I want to see evidence of such an increase before endorsing less accommodative policy action by the FOMC," Bullard said at the New York Association for Business Economics.
Kansas City Fed President Esther George, the lone dissenter on the Fed's Open Market Committee, said the Fed created confusion in the market and it risks credibility by delaying the reduction of its bond buying program.
(Read more: No Fed taper this year, says former Bush advisor)
Lazard Capital's Hogan also said two "hurdles" still remain for investors in September—the German election and Washington's ongoing budget debate.
"Those two could prove to be formidable and not bullish for stocks if they move in the wrong direction," he explained. "So as we head into the weekend, investors are taking money off the table."
Meanwhile, the U.S. House of Representatives passed a bill that would keep the government open to Dec. 15 and also eliminate funding for President Barack Obama's "Obamacare."
(Read more: Stocks are about to plunge, Wells Fargo pro warns)
In a busy week for IPOs, shares of advertisement technology company Rocket Fuel more than doubled in their market debut, a day after the company priced at the top end of its revised price range.
"It's been a pretty good year for IPOs and things are starting to catch fire again…I won't say we're back quite to dot-com, but we're beginning to bubble up," said Art Cashin, director of floor operations at UBS Financial Services.
Darden Restaurants slumped to lead the s&P 500 laggards after the parent company of Olive Garden and Red Lobster posted a much lower-than-expected profit and warned that sales are likely to remain weak at its restaurant chains.
Apple reversed its initial gains along with the broader market as the tech giant's new iPhone 5C and iPhone 5S went on sale in stores around the world.
(Read more: Record iPhone debut isn't a 'victory lap' yet: Pro)
Facebook advanced to hit a record high after Cowen upgraded the social-networking giant to "outperform" from "market perform" and lifted the price target to $53 from $29.
In Asia, markets in China, Hong Kong and South Korea were shut for public holidays. Indian stocks led those markets that were open lower, after the Reserve Bank of India unexpectedly raised benchmark rates. Japan's Nikkei index closed just below the flatline and Australia's S&P ASX 200 fell off the previous session's five-year high.
—By CNBC's JeeYeon Park (Follow JeeYeon on Twitter: @JeeYeonParkCNBC)
Coming Up Next Week:
MONDAY: New Dow components added, Chicago Fed activity index, PMI manufacturing index flash, Fed's Lockhart speaks, Microsoft Surface event; Earnings from RedHat
TUESDAY: Fed's Pianalto speaks, FHFA home price index, S&P Case-Shiller index, consumer confidence, Richmond Fed mfg index, Fed's George speaks, 2-yr note auction; Earnings from CarMax, Lennar, KBHome
WEDNESDAY: Mortgage applications, durable goods orders, new home sales, oil inventories, 5-yr note auction, Samsung Galaxy products available; Earnings from AutoZone, Bed Bath & Beyond
THURSDAY: GDP, jobless claims, corporate profits, pending home sales, natural gas inventories, Fed Kocherlakota speaks, 7-yr note auction, Fed balance sheet/money supply, Fed's George speaks, weekly rail numbers; Earnings from Nike, Accenture
FRIDAY: Fed's Evans speaks, personal income & outlays, consumer sentiment, Fed's Dudley speaks, farm prices; Earnings from BlackBerry
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