The founder of Hindenburg Research says it is closing its short-selling research shop.

Hindenburg Research, the startup research and investment firm that made a name for itself with a string of successful short bets, is closing, founder Nate Anderson announced Wednesday.

“As I’ve been sharing with family, friends and our team since late last year, I’ve decided to disband Hindenburg Research. The plan is once we’ve finished the pipeline we’ve been working on. And we’ve completed the last of the Ponzi cases we’re sharing with regulators, and that day is today,” Anderson said. He wrote Note Posted on the organization’s website.

Andersen founded Hindenburg in 2017, and the company has since published negative research reports on dozens of companies. One of Hindenburg’s first high-profile reports came in 2020 and focused on vehicle launches. Part of the report included allegations that Nikola had faked the self-driving capabilities of a semi-truck in a video, which the company later admitted. Nicola’s founder Trevor Milton was later sentenced to four years in prison.

Many of the targets of the Hindenburg Reports were small companies. The company has followed major financial figures including Carl Icahn Icahn Enterprises L.P and Indian billionaire Gautam Adani’s business empire.

The company’s most recent report on the auto retailer was on January 2. CaravanHe called it “father and son accounting of the ages”. In a statement, Carvana called the company’s report “deliberately misleading and inaccurate.” The stock fell more than 11% the day after Hindenburg published the report, but has since recovered.

Hindenburg was a short seller as well as a research house. This means that the firm is placing bets on the companies it is researching, allowing it to profit if the stock declines. As Hindenburg’s reputation grew, some stocks saw negative reactions immediately after the reports were published.

It is not clear how much money Hindenburg made from his short bets.

Hindenburg’s departure came at a time when the controversial practice of short selling was falling out of favor elsewhere. The meme-stock craze of 2021 pitted retail investors against hedge funds, prompting some professional investors to pull back from short selling. Federal authorities have been investigating other short sellers in recent years, including the Justice Department, which last year charged Citroën’s Andrew Grau with securities fraud.