Short seller Andrew Left's Citron Research has initiated a position against Riot Blockchain.
Shares have soared more than 375% since the company pivoted to blockchain from biotech in October.
Riot Blockchain shares are shrugging off the news of Left's short position.
Shares of Riot Blockchain are shrugging off the news that short seller Andrew Left's company, Citron Research, has initiated a position against the company.
They're trading up 33.5% near $38 apiece on Monday.
Riot Blockchain has soared about 375% since the company announced in early October that it was pivoting to focus on buying cryptocurrency and blockchain businesses.