Gilbert is the majority shareholder of the company, with roughly 1.9 billion shares. That sent his worth soaring by nearly $33 billion after Rocket shares, well, skyrocketed 71% Tuesday. The paper gains moved him up 19 spots on the Bloomberg Billionaires Index—the biggest one-day move in the list’s history.

Newton’s law applies to Wall Street as well, though. As of 12:10 p.m. ET today, Gilbert had lost $19 billion of those gains.

Rocket’s volatility comes after a short squeeze sent the stock’s price to a close of $41.60 on Tuesday. (The stock was one of the most heavily shorted in the country.) Some analysts pointed to Reddit’s r/WallStreetBets community as the source of the surge. (That board has an active thread about the stock today, with over 14,500 comments—though many of those commenters seem less enamored with the stock than the community was and continues to be with GameStop.)

Rocket, which is the parent firm of Quicken Loans, went public last year and has traded in the $20 range for most of its time as a public company. Many analysts say it’s likely to return to that territory after the surge in interest from individual investors wanes.

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