A hedge fund lost 10% in just a few days after a sudden spike in AMC stock derailed an options trade

Hedge fund Mudrick Capital lost 10% in just a few days of trading as shares of meme stock AMC Entertainment spiked to record highs, the Wall Street Journal reported , citing people familiar with the matter.

The losses were driven by call options sold by firm founder Jason Mudrick, according to the WSJ. The position, intended to serve as a downside hedge, ended up backfiring as the stock surged too much, too fast.

The runaway share spike occurred on June 2, when AMC shares rose as much as 127%, to $72.62, well beyond the strike price of $40 for Mudrick’s options.

Just one day prior, Mudrick had disclosed a $230.5 million purchase of new AMC stock , then immediately sold those shares at a profit, according to a Bloomberg report. Despite the success of that leg of the overall AMC trade, Mudrick’s calls on the stock were still held short, leaving them vulnerable to the June 2 surge, the WSJ found.

Mudrick did close out all options and debt positions on June 2, albeit too late to avoid the squeeze. While the fund did earn a roughly 5% return on the debt, it ended up absorbing a net loss of 5.4% because of the options trade.

Though the fund took a hit amid the surge, it’s still up about 12% for the year, the Journal said. Meanwhile, AMC, the world’s largest movie theater chain, is up more than 2,000% year-to-date.

Retail traders have been dealing blows to short sellers and hedge funds this year as they’ve poured into stocks with high short interest rates in order to force a short squeeze. Earlier this year, investors on Reddit’s Wall Street Bets led a share price surge in GameStop, which caused short sellers to lose billions.

Amid the renewed meme-stock interest in recent weeks, short sellers have continued to lose money in retail-trader favorites like AMC and GameStop. The meme stock trade has scared off many short sellers from heavily betting against certain stocks.