Data from financial analytics firm Ortex revealed on Monday that shorting shares in GameStop cost hedge funds a total $12.5 billion over January.
The losses were inflicted by small-time investors who piled into GameStop, pushing up the shares and forcing many hedge funds to buy them back to cover losses. GameStop shares are up 1600% year-to-date.
Ortex data showed $5.9 billion worth of GameStop shares were out on loan as of Friday or 49% of the total freefloat.
In Europe, short-sellers booked $28 million loss on their bets against Cineworld. Almost 24% of its freefloat is on loan.