Twitter is on pace to be biggest loser in S&P 500 for third quarter

Twitter just seized a title no company wants: the worst performer in the S&P 500 Index. Its sharesdropped about 35 percent in third-quarter trading, which ended Friday — worse than every other company in the index.
 
Twitter’s tough quarter was set off by a disappointing earnings report. The stock plunged the most in four years after the firm said in July that monthly users had dropped by 1 million in the second quarter and predicted further declines as it fights against spam, fake accounts and malicious rhetoric. Shares sunk further earlier this month after an analyst at MoffettNathanson flagged “smoke and mirrors” in the company’s expense reporting.

 
Short interest has risen to almost 8 percent of float, according to data from financial-analytics firm S3 Partners. That compares with less than 5 percent at the end of July.
 

Meanwhile, Twitter CEO Jack Dorsey’s other company has been on fire. Shares of Square closed at a record high Friday, finishing the quarter as the second-best performer in the Russell 1000 Index.
 
The worst quarterly performers in the S&P 500 after Twitter are IPG Photonics with a 29 per cent drop and Western Digital with a 24 per cent decline.