Investors selling GameStop short - betting the stock price would decline - posted $664 million in mark-to-market losses as shares of the gaming retailer rocketed 104% into the close, according to financial analytics firm S3 Partners.

GameStop first spiked higher last month as day traders uniting in online forums like the Wall Street Bets subreddit scooped up shares in hopes of driving a massive short squeeze.

Yet a last-minute rally on Wednesday reignited the buying frenzy and prompted new calls on Wall Street Bets to drive a new short squeeze.

"While there were some buy-to-covers brought about by the large mark-to-market losses, they were offset by new short sellers looking for a pullback from this volatile price move," he said.

The number of GameStop shares shorted over the past week rose by 1.97 million, marking an increase of 15%

Short interest in the stock is $1.42 billion, or 28.4% of the company's tradeable shares

The number of shares sold short can decline even further if GameStop's stock price holds, Dusaniwsky said