(Bloomberg) -- AMC Entertainment Holdings Inc.’s stock price briefly quadrupled Wednesday, erasing last year’s pandemic-induced slump, before triggering several trading halts as it pared nearly half of those gains. The cinema operator is among a number of heavily shorted stocks rallying this week.Shares rose as much as 310% at the open of the regular trading session in New York, pushing it to the highest level since October 2018. The stock has been trimming gains since then, triggering at least four trading halts for volatility. AMC said Monday that $917 million in new funds would get it through the next six months as the industry battles the effects of Covid-19, which has shuttered venues around the world.Bloomberg Intelligence analyst Amine Bensaid said AMC is one of the names that’s been floated in social media for its high short interest, joining the likes of GameStop Corp. and Express Inc.The gain “isn’t based on fundamentals and appears to be similar to the GameStop run-up driven by retail investors, yet could help ease a severe liquidity crunch if the company capitalizes on the jump and issues additional shares,” Bensaid wrote Wednesday.AMC shares pared about half of their steepest gains, advancing 174% to $13.40 as of 10:09 a.m. in New York. Volume was eight times higher than the three-month average.Short interest as a percentage of free float was 12%, according to data from S3 Partners, down from 61% in December. In London, shares of Cineworld Group Plc, another favorite among short sellers, jumped as much as 21%. The U.K. firm competes with AMC’s Odeon unit in Britain.AMC’s bonds also continued their tear along with the shares, reaching record highs and leading the U.S. high-yield market on Wednesday. The notes due 2026 reached roughly 63 cents on the dollar, up from a low of 5 cents set in November, according to Trace bond trading data.(Updates share move, adds trading halts)For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2021 Bloomberg L.P.