Athletes Are the New Media Buy

During a playoff broadcast last week, a Kalshi commercial aired featuring Ronald Acuna Jr., making the Braves outfielder the first MLB player to sign with a prediction market. He is not the first athlete to take that deal. Bryson DeChambeau got there earlier this year, followed by Giannis Antetokounmpo and Lionel Messi. Meanwhile Polymarket is running a multimillion-dollar campaign built around LeBron James, Eli Manning and Richard Sherman. The endorsement market has a new buyer, and it is spending like the category depends on it.

Because it does. Last weekend alone, NFL and college football games pushed Kalshi and Polymarket to consecutive daily trading records, a two-day total of $8.56 billion. The platforms are growing on the back of sports, and they are buying the faces of sports to prove it.

Why athletes, and why now

Prediction markets have a awareness problem that money alone cannot fix. Most casual fans still cannot explain what trading a contract is, and the platforms know it. An athlete does two things at once: borrows trust from a face fans already believe in, and translates the product into the language of fandom. When Acuna appears in a Kalshi spot during a Braves playoff game, the message is not about derivatives. It is that this is a thing baseball people do.

There is also a timing play. Kalshi has already partnered with five MLB clubs, including the Red Sox, Dodgers and Braves, and is reportedly in talks with the league itself. The NBA, the last major league without a formal position, is expected to announce a deal with prediction platforms within weeks. Locking up marquee talent now, before league-wide frameworks settle the rules, is a land grab.

The scrutiny is part of the story

Not everyone is applauding. MLB has a long and painful history with gambling, and an active player fronting a trading platform will draw a kind of attention that a beer sponsorship never would. The NFL has gone further, asking the Supreme Court to weigh in on whether sports contracts are wagers at all. Every athlete who signs becomes a data point in that fight, whether they want to be or not.

That tension is exactly why the brands are paying a premium. In a category where the product is under regulatory fire, credibility is the scarcest asset on the market, and athletes are the fastest way to buy it.

What this means for brands in the space

• Talent is now a positioning decision, not a media line item. The athlete you sign tells fans what kind of platform you are before the ad says a word.
• Fit beats fame. A beloved regional star who genuinely uses the product will outwork a global name reading a script.
• Build for scrutiny. If the league, a regulator or a columnist looks hard at the deal, the creative and the contract both need to hold up.
• Move before the frameworks land. Once leagues formalize their rules, the best faces will be priced like Super Bowl inventory.

The sportsbooks spent a decade buying commercials. The prediction markets are buying the people in them. Watch which strategy fans remember.