Wall Street dropped on Thursday, weighed down by Apple as well as selling in Wells Fargo, Citigroup and other major banks as investors worried about the health of Deutsche Bank.
The S&P 500 financial index .SPSY declined 1.49 percent after Bloomberg reported that some hedge funds have withdrawn excess cash and positions held at the German lender.
Growing concerns over the stability of Germany's biggest bank have pushed its shares to record lows and its U.S.-listed stock (DB.N) on Thursday tumbled 6.7 percent.
"This Deutsche Bank story is really casting a very long shadow over equity markets," said Peter Kenny, senior market strategist at Global Markets Advisory Group, in New York. "In some respects, it speaks to fears over large money-centre banks having serious problems, and the last time we had that conversation was the financial crisis."
Adding to negative sentiment in the banking sector, Wells Fargo & Co (WFC.N) lost 2.07 percent after U.S. lawmakers rebuked CEO John Stumpf over his handling of sales abuses.
Citigroup (C.N) dropped 2.28 percent and JPMorgan Chase (JPM.N) fell 1.59 percent.
Apple (AAPL.O) fell 1.55 percent after Barclays cut its price target. The stock was the biggest drag on Wall Street.
The S&P healthcare index .SPXHC lost 1.84 percent and also weighed heavily on the S&P 500 as shares of Merck (MRK.N) and Johnson & Johnson (JNJ.N) declined.
Among the gainers, Qualcomm (QCOM.O) jumped 6.3 percent after the Wall Street Journal reported the chipmaker is in talks to buy NXP Semiconductors (NXPI.O). NXP surged 16.88 percent.
Up 5 percent this year, the S&P 500 is trading near 16 times expected earnings, above its 10-year average of 14, according to Thomson Reuters Datastream.
"Equity valuations are stretched and priced for perfection," said Mike Baele, managing director with the private client reserve group at U.S. Bank in Portland, Oregon. "I would not be surprised to see additional volatility."
The CBOE Volatility Index .VIX, a gauge of near-term investor anxiety, jumped 14 percent.
The Dow Jones industrial average .DJI slid 1.07 percent to 18,143.45 points at the close, its sharpest decline since Sept 13.
The S&P 500 .SPX lost 0.93 percent to end at 2,151.13 and the Nasdaq Composite .IXIC dropped 0.93 percent to 5,269.15.
The S&P utilities index .SPLRCU, which is sensitive to interest rates, fell 1.45 percent, its fifth day of losses in a row.
Oil prices were up a day after OPEC members agreed to curb production, even as analysts raised questions about the effectiveness of the deal.
Declining issues outnumbered advancing ones on the NYSE by a 3.87-to-1 ratio; on Nasdaq, a 3.09-to-1 ratio favoured decliners.
The S&P 500 posted 22 new 52-week highs and 4 new lows; the Nasdaq Composite recorded 82 new highs and 35 new lows.
About 7.7 billion shares changed hands on U.S. exchanges, above the 7.0 billion daily average for the past 20 trading days, according to Thomson Reuters data.
(Additional reporting by Chuck Mikolajczak in New York and Yashaswini Swamynathan in Bengaluru; Editing by Nick Zieminski)