Milwaukee Bucks star Giannis Antetokounmpo has become a shareholder in Kalshi, a major prediction market with a wide array of sports trading opportunities.

Antetokounmpo announced the partnership Friday.

“The internet is full of opinions. I decided it was time to make some of my own,” Antetokounmpo posted on social media. “Today, I’m joining Kalshi as a shareholder.”

Kalshi said Antetokounmpo is the first basketball star to join the company as a shareholder. The partnership includes help with live events and marketing.

“Giannis is a legend,” Kalshi CEO Tarek Mansour said in a release. “He’s exactly the type of long-term partner we want to align our growing brand with, and we couldn’t be happier he’s on board.”