Market watchers identified dozens of stocks potentially vulnerable to extreme volatility after a buying spree from an army of retail traders in recent days prompted hedge funds to unwind their bets against GameStop and other companies, fueling surges in their share prices in a phenomenon known as a “short squeeze.”

“Unfortunately, it’s definitely not a one-off thing,” said Randy Frederick, vice president of trading and derivatives at the Schwab Center for Financial Research. “The type of activity that drove that higher, I believe, has caused people to try to duplicate that in other names.”

J.P. Morgan earlier this week named 45 stocks that may be susceptible to short squeezes and similar “fragility events,” including real estate company Macerich Co, restaurant chain Cheesecake Factory Inc and clothing subscription service Stitch Fix Inc.

Like GameStop, American Airlines Group Inc, AMC Entertainment Holdings Inc and others that have recently become targets of retail traders in recent days, all the stocks have high short interest ratios.

That means a large percentage of investors have borrowed the stock to sell it in anticipation that they will be able to buy it back at a lower price and profit on the trade. But if the stock rises sharply, those investors may be forced to buy back the stock at a loss.

“The unfortunate events in GameStop this week may be building a dangerous precedent for markets whereby retail investors act en masse to leverage their buying powers to spark fragility events,” analysts at J.P. Morgan said in a note.

Using derivatives and coordinating buying on websites such as the Reddit forum wallstreetbets, retail investors have had an outsize impact on markets in recent months. Hedge funds Melvin Capital Management and Citron Capital closed out short positions in GameStop earlier this week after buying pressure pushed up the company’s shares.

GameStop shares were recently down 25% on Thursday as retail brokerages Robinhood Markets Inc and Interactive Brokers Inc, restricted purchases of the stock, along with several others that have catapulted in recent days, including AMC Entertainment Group Inc and BlackBerry Ltd.. Even so, the video game retailer’s shares have gained more than 500% since last Thursday.

Barring wider trading restrictions, similar patterns could play out over several weeks as short sellers unwind their bets, said Michael Purves, chief executive of Tallbacken Capital Advisors.

Some firms run strategies that involve holding both long and short positions on a stock, he said, and as a result, certain stocks could see a surge and then a sharp drop as those firms adjust their positions. That process could put pressure on stocks more broadly and contribute to market volatility.

“I do think the contagion risk is real,” Purves said. “Any stock that is heavily shorted is exposed to getting GameStopped.”