Samuel Bankman-Fried, the head of Bahamas-based cryptocurrency exchange FTX, revealed a 7.6% stake in Robinhood, capitalizing on the beaten-up stock to build a position.
A regulatory filing said he did not have any intention of taking control of Robinhood but that he could end up pushing for changes.
A person familiar with the matter said Bankman-Fried had not informed Robinhood of any plans to merge it with his FTX platform.
According to the SEC filing, the crypto billionaire now owns more than 56 million shares of Robinhood, which he purchased for more than $648 million.
Robinhood has struggled to meet Wall Street expectations since the company's IPO last year and, like many tech start-ups, has yet to turn a profit.
The company - popular with younger, retail investors - reported a 43% decline in first-quarter revenue along with a decline in monthly active users in April, amid a steep stock market selloff.
And, even with Friday's bounce, shares of Robinhood are down a whopping 87% from their all-time high.
