Reddit co-founder Alexis Ohanian scored a $50 million windfall from an early bet on cryptocurrencies that helped him seal his love match with tennis legend Serena Williams.

Ohanian, 39, revealed in an interview with Forbes that he used a portion of his profits to buy a $3 million, 17-carat engagement ring when he proposed to Williams in December 2016.

Williams, who won a record 23 major singles titles before retiring last year, married the tech entrepreneur in 2017.

Ohanian said he earned the $50 million through an early investment in the cryptocurrency exchange Coinbase and by buying up ether, a leading cryptocurrency token that ranks just behind bitcoin in popularity.

Ohanian told the outlet he learned about the token during his early meetings with Coinbase executives in 2014.

He invested $15,000 to buy 50,000 ether. Today, a single ether token is worth about $1,651, meaning Ohanian’s original stake would be worth nearly $83 million.