(Reuters) - Short sellers betting against MicroStrategy ( MSTR ) have lost $1.92 billion since March, according to data from S3 Partners, highlighting the hit from a rally that has helped the stock outperform bitcoin.

The approval of several spot bitcoin exchange-traded funds (ETFs) by the Securities and Exchange Commission (SEC) in January has brought the once-nascent asset class closer to the mainstream.

Traders betting against crypto exchange Coinbase and bitcoin miner CleanSpark ( CLSK ) also lost $593.50 million and $106.40 million, respectively, the data showed.

MicroStrategy ( MSTR ) held nearly 190,000 bitcoin on its balance sheet as of the end of 2023 and has indicated it would continue increasing its exposure. It sold convertible debt twice within a week last month to raise money to buy more bitcoin.

"The premium (for MicroStrategy ( MSTR )) is supported by a desire for investors to have exposure to bitcoin who may be unable to invest directly in bitcoin or in ETFs," analysts at BTIG said in a note earlier in April.

The company's ability to raise capital to purchase additional bitcoin is also a positive for shareholders, the brokerage added.

But despite the recent optimism, the crypto industry continues to be heavily shorted. Short interest in nine of the most-watched companies in the crypto space stood at 16.73% of the total number of their outstanding shares, more than three times the average in the United States.

The SEC also remains uncomfortable with crypto and its approval of the spot bitcoin ETFs might not signal willingness to embrace other similar products, like spot ethereum ETFs, Reuters has reported.

The spot bitcoin ETF decision was not "indicative of a change in philosophy at the Commission," said Alan Konevsky, chief legal and corporate affairs officer at online investment platform tZERO.

"I don't think it's a harbinger of more good things to come," he said.

Short sellers sell borrowed shares and hope to buy them back at a lower price later, pocketing the difference.