It’s getting harder and harder to be a Tesla Inc. short seller.

Tesla TSLA, -4.04% stock’s 20% rally resulted in paper losses of about $2.5 billion on Monday alone for short sellers, S3 Analytics said in a note.

Tesla set a record close of $780 and an intraday record high of $786.14 on Monday, and the 20% rally was the stock’s largest one-day percentage increase since May 9, 2013, when it rose 24.4%. That was a day after Tesla posted its first-ever quarterly profit.

“Everyone is anticipating a dramatic (Tesla) short squeeze, but it is more likely to be a continuous slow decline in shares shorted rather than a sudden abrupt plunge,” said S3, a financial technology and analytics firm. That’s because of different types of hedging, the analysts said.

“While we are seeing some momentum short sellers increasing their positions in anticipation of a short-term pullback, we should see an increase of short-covering due to this $700/share level squeeze,” they said.

See also:Tesla stock rockets past $700 after analyst sets new Street-high target

Tesla’s rally prompted Chief Executive Elon Musk to tweet simply flame emojis about one hour into the extended session on Monday:

Tesla shorts, or those betting the stock price will fall, were down $2.89 billion in mark-to-market losses in 2019 and are down $8.31 billion in mark-to-market losses so far in 2020, including the day’s $2.5 billion pinch, S3 said.

Tesla last week reported a stellar quarter complete with news that the Model Y, its compact SUV, is being made ahead of schedule and the company hopes to sell more than half a million vehicles in 2020.

The stock has been on a tear since mid-December, and Monday’s record close was its 19th since then. Tesla was the best-performing and the most active stock in the Nasdaq 100 on Monday.

Read more:Tesla earnings win praise even from doubters: ‘We fully admit things are better than we expected’

Short-seller interest on Tesla is around $16 billion, with 24.38 million shares shorted, or about 18% of its float. It has been the largest short in U.S. equities, with Apple Inc. AAPL, -2.04% No. 2 with about 0.9% of its float.