A stumble by Apple set off the worst rout in the stock market since July on Thursday.
The selling started early and picked up strength in the afternoon. By the close of trading, all 30 big companies in the Dow Jones industrial average and the 10 industries in the Standard & Poor’s 500 index lost ground.
Most investors said the drop wasn’t a sign of worry as all the forces behind the market’s long rally remain in place. It was only a week ago that the S&P 500 touched a record high, and strong runs are usually followed by short breaks. The index has lost 2 percent this week but is still up 6 percent for the year.
“There’s just an absence of real news to chew on,” said Mark Luschini, the chief investment strategist at Janney Montgomery Scott. “When you’re at a peak, markets need more and more good news to keep climbing.”
The S&P 500 index lost 32.31 points, or 1.6 percent, to close at 1,965.99.
The Dow slumped 264.26 points, or 1.5 percent, to close at 16,945.80. The Nasdaq composite, which is dominated by technology companies, dropped 88.47 points, or 1.9 percent, to 4,466.75.
It was the worst day for all three indexes since July 31.
Technology companies were hit hardest. Apple dropped nearly 4 percent following its announcement late Wednesday that it had pulled a software update which prevented users from making phone calls. Others complained that they bent their new iPhones by sitting on them. Apple lost $3.88 to $97.87 in heavy trading.
Two economic reports out Thursday were little help. Claims for unemployment benefits crept up last week. But the less volatile four-week average fell. A separate report said businesses orders for equipment plunged last month, mainly a result of falling orders for commercial aircraft.
“The economic numbers were negative, but not alarming and don’t change the direction of the economy at this time,” said Peter Cardillo, chief market economist at Rockwell Global Financial.
Henry Smith, chief investment officer at Haverford Trust, said there was no fundamental reason behind the drop on Thursday. A sudden turn might seem alarming because it’s so unusual.
“We’ve really had such little volatility for the past couple of years,” Smith said. “Now when we have a 200-point drop in the Dow, it feels like something is really wrong.”
Trading this week has turned increasingly turbulent, an abrupt break from a sleepy summer. On Monday, concerns about slowing growth in China and falling U.S. home sales knocked the market back, giving the S&P 500 its worst daily drop in more than a month. On Wednesday, the S&P 500 had its best gain in more than a month.
Some investment professionals have been warning that the market has been calm for too long and say a 10 percent drop, known as a “correction,” is overdue. Since World War II, they typically hit every 18 months, according to S&P Capital IQ. The last one occurred in August 2011.
“Big pullbacks are normal in a bull market,” said Smith. “What’s abnormal is that we’ve gone three years without one.”
Bill Strazzullo, chief market strategist at research firm Bell Curve Trading, thinks stocks could fall further as the S&P 500 slips toward 1,950. He said the money that investors poured into stocks when the index crossed above that mark could be pulled out.
“You could get people wanting to liquidate,” Strazzullo said. “If you go below 1,950, the market can easily correct 10 percent, maybe more.”
The dollar has been gaining on other major currencies as traders expect the Federal Reserve to start raising its key interest rate next year. The world’s other major central banks are expected to sit tight or take other steps likely to weaken their currencies. On Thursday, the euro fell 0.2 percent to $1.275. The dollar fell to 108.73 yen.
Prices for U.S. government bonds jumped, driving the yield on the 10-year Treasury note down to 2.50 percent from 2.57 percent late Wednesday.
In commodity trading, gold rose $2.40 to $1,221.90 an ounce. Silver slipped 26 cents to $17.44 an ounce and copper lost two cents to $3.03 a pound.
The price of oil fell slightly on ample global supplies despite U.S. airstrikes against oil facilities controlled by the Islamic State group in Syria. Benchmark U.S. crude fell 27 cents to close at $92.53 a barrel on the New York Mercantile Exchange. Brent crude, a benchmark for international oils used by many U.S. refineries, rose 5 cents to close at $97.00 on the ICE Futures exchange in London.
In other energy futures trading on the NYMEX, wholesale gasoline rose 5.4 cents to close at $2.718 a gallon, heating oil rose 0.7 cent to close at $2.696 a gallon and natural gas rose 6 cents to close at $3.971 per 1,000 cubic feet.
—MATTHEW CRAFT, AP Business Writer | AP Business Writer Bernard Condon and Markets Writer Steve Rothwell contributed.