(Reuters) - Traders who have sold Tesla Inc shares short have lost about $6.08 billion on a mark-to-market basis during the electric car maker's current winning streak, according to the latest data from S3 Partners.
Tesla's current rally, which will span 11 sessions if it closes Friday's session higher, has the stock up around 35% since May 24.
Investors who sell securities 'short' borrow shares and then sell them, expecting the stock to fall so they can buy the shares back at the lower price, return them to the lender and pocket the difference.
And Tesla is the largest short in the world, according the S3's head of predictive analytics Ihor Dusaniwsky, who says $22.43 billion worth of Tesla shares have been sold short.
But even as Tesla's shares have risen short sellers have been adding to their bets since April "as short sellers were not convinced the long buying price support would continue and a price retracement would be inevitable," Dusaniwsky said.
Traders have shorted 15.3 million new Tesla shares, worth $3.6 billion, in 2023. And in the past thirty days bearish bets expanded further, with 1.3 million more shares worth $303 million, sold short, representing a roughly 1.4% increase even as Tesla's stock price rose 39%, Dusaniwsky said.
Tesla shares on Friday traded up 4.4% at $245.08 after earlier hitting its highest level since early October.
(Reporting By Sinéad Carew; editing by Lance Tupper, Chris Reese, Chizu Nomiyama)