For a stock market that’s gone up as fast as this one, there’s a lot of pain going around.

The Standard & Poor’s 500 Index has climbed almost 11 percent since falling to a 10-month low on Aug. 25, restoring about $1.4 trillion to share prices. Meanwhile there have been 13 instances in the past two weeks of companies posting one-day drops of 10 percent or more — one of the highest incidences of single-stock crashes in four years.

“It seems everybody the last month had a five-day period where they got wiped out,” Tom Lee, managing partner and co- founder of New York-based Fundstrat, said by phone Monday. “Anybody who made concentrated bets is hurting right now. It’s been a war. You had to be a ninja to come away unscathed during this rally.”

Aside from a spate of declines triggered by concerns in the specialty drug industry, the common theme in the crashes has been disappointing earnings. Companies in the S&P 500 are already forecast by analysts to report the weakest earnings since the bull market began, with income falling an estimated 6.1 percent from a year ago in the third quarter.

Railroad Kansas City Southern plunged 11 percent on Oct. 16 after saying auto shipments may be damped in early 2016. Hospital operators Universal Health Services Inc. and Tenet Healthcare Corp. fell 11 percent and 19 percent on Thursday on a rival’s forecast.

Stark Example

Last Thursday provided a particularly stark example of the disparity among gains and declines. Even as the S&P 500 climbed 1.7 percent and the average stock that rose added 2.3 percent, companies that fell lost an average 2.5 percent. The 4.8- percentage-point spread was the third-biggest since July 2012, with the two more extreme days occurring at the height of selling in August.

Apart from one week in November 2014 when a plunge in the price of oil sent energy-related companies tumbling, the two weeks from Oct. 14 through Friday saw the highest rate of declines of 10 percent or more going back to 2011. On that year’s “Black Monday,” when the S&P 500 sank 7 percent amid a downgrade of the U.S. debt rating, almost 100 stocks in the index fell at least 10 percent.

Face-Ripping

“It’s been a face-ripping rally for a lot of people,” said Fundstrat’s Lee. The most bullish strategist on Wall Street — Lee has stood by his call for the S&P 500 to reach 2,325 by year-end — told clients in a late September note that losses wouldn’t dip below the low reached on Aug. 24, and to be poised for a rally.

“I think everyone missed it,” he said Monday. “The selloff turned everyone bearish, they’re looking for things to quibble with.”

The list of stocks posting single-day drops of 10 percent or more in the last two weeks includes some of the market’s biggest stars, including Wal-Mart Stores Inc. and Harley Davidson Inc. Others are Stericycle Inc., the Lake Forest, Illinois-based medical waste manager that plummeted 19 percent Friday after reporting disappointing profit and sales, and Greensboro, North Carolina-based VF Corp., which lost 12 percent on a reduced earnings forecast.

The most visible pain has been for funds invested in Valeant Pharmaceuticals International Inc. The hedge fund favorite lost nearly 40 percent of its value over four days following accusations of fraud, delivering a blow to ValueAct Holdings LP and Bill Ackman’s Pershing Square Capital Management.

Thirty-two hedge funds counted Valeant among their top 10 holdings at the end of the second quarter, with the stock accounting for 10 percent of the portfolios of those funds on average, according to an Aug. 19 report by Goldman Sachs Group Inc.

Navigating the recovery has been treacherous. Odey European, the London-based $1.4 billion hedge fund managed by Crispin Odey, plunged 17 percent in the first 16 days of October, according to a person with knowledge of the situation.