(Bloomberg) -- Carvana Co. shares have doubled this year, and more head-scratching moves could be in store for the debt-strapped online used-car retailer amid bets the rally won’t last.

More than 266,000 call contracts on Carvana changed hands in New York Monday, the second-highest level ever and more than triple the average volume in the past 20 days, according to data compiled by Bloomberg. The shares closed with a 29% rally.

Retail traders have been eagerly riding the wave of Carvana’s rally that brought back the memories of the meme-stock mania of 2021. Yet at $10 a share, Carvana is far from the $370 level it enjoyed in August 2021. It plunged 98% last year as rising borrowing costs, concern over rising inflation and falling used-car prices crimped the firm’s growth outlook.

And its 2023 rally has attracted growing bets that the stock will lose momentum.

Among the companies in the Russell 1000 Index, Carvana holds the highest short interest, almost 60% of free float, according to IHS Markit’s data. It’s also the biggest gainer in the equity gauge this year. With one day to go, Carvana is up 111% so far in January, on track for its best month ever. 

(Updates prices throughout)

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