Short sellers made a killing from Under Armour's crash

On Tuesday, shares of Under Armour crashed more than 20% after the company announced disappointing top and bottom line results while also lowering its full-year 2017 guidance. The company earned $0.23 per share on revenue of $1.31 billion and lowered its 2017 operating income forecast to $320 million.

And while shareholders took it on the chin as the stock plunged following the results, the short sellers raked in a profit of more than $400 million, according to data provided by S3 Partners. Tuesday's big haul has created a reversal of fortune for the shorts, who were holding a loss of $17.5 million net of financing expenses on their books for the month of January before shares tumbled on Tuesday.

Over the last 13 months, Under Armour short sellers have been the most successful in the apparel space, reaping a gain of $196 million profits net of financing, S3 Says.

Markets Insider