Investors who bet against Tesla stock have lost $5.5 billion in the four sessions since the electric car maker promised more affordable cars, according to data from S3 Partners.

The stock has soared almost 40% since the April 24 announcement, including a nearly 16% jump on Monday, when the automaker cleared some key regulatory hurdles that had long hindered the roll-out of its self-driving software in China.

Monday’s surge cost the short sellers $2.93 billion and turned April unprofitable with losses of $2.11 billion, according to the analytics firm.

Still, with the company’s shares down nearly 20% for 2024, profits booked by bearish Tesla investors stand at $4.10 billion for the year so far.

“This has not been a short squeeze as we have actually seen short selling into this rally with over 2 million new shares shorted over the last week,” said S3’s head of predictive analytics Ihor Dusaniwsky.

A short squeeze happens when these investors are forced to quickly cover their bets to limit losses if a stock gains ground instead of falling.

Tesla is the third-largest U.S. short behind Nvidia and Microsoft, Dusaniwsky said, noting that $18.53 billion, or 3.97% of its publicly available shares, are in short position.

The Elon Musk-led company’s plan to roll out cheaper models has eased some worries about its slowing growth and came after a tumultuous week marked by big layoffs, executive exits and price cuts.