Tesla posted a surprise third-quarter profit—shares surged as much as 21 percent

Tesla announced its first profit in almost a year, at $143 million, significantly exceeding wallstreet expectations.

While the news cost Tesla short-sellers USD $1.4 billion in mark-to-market losses, the earnings suggest the company is now focusing on cost controls after a big-spending phase to ramp up Model 3 production.

Shares rose nearly 21 percent to $307.12 after hours on the unexpected news, crossing $300 for the first time since March 1.

“Super proud of Tesla team for great execution and support of Tesla customers greatly appreciated!” tweeted the chief executive Elon Musk about the results.

Elon Reeve Musk born June 28, 1971) is a technology entrepreneur, investor, and engineer. He holds South African, Canadian, and U.S. citizenship and is the co-founder, CEO, and product architect of Tesla, Inc.

Sales of Tesla Model 3 vehicles far outpace the company’s older Model S and Model X vehicles.

Tesla delivered 17,483 Model S and Model X vehicles in the third quarter, compared to 79,703 Model 3 cars.

CEO Elon Musk anticipates the Model Y, which has yet to be produced, could surpass Model 3 sales.

Musk peppered investors with positive updates: Tesla’s new factory in China is already starting production, the Model Y crossover will launch months earlier than expected next year and the long-languishing energy business is showing signs of life.

Traders betting against the company got crushed after the earnings report was released.

According to data from financial-analytics provider S3 Partners, Tesla short-sellers absorbed $1.4 billion in mark-to-market losses after shares rallied as much as 20 percent.

The gains wiped out close to 70 percent of Tesla short-sellers’ profits for the year, S3 wrote in a research note Thursday.

With about $8.31 billion in short interest, Tesla is the second-most shorted stock in the US equity market behind Apple, according to S3.