Americans will wager an estimated $3.1 billion on March Madness this year, according to the American Gaming Association.

That’s up 15% over last year, driven in part by increased betting on the women’s tournament. However, despite rapidly growing fan interest, opportunities to legally wager on women’s sports still lag. 

In last year’s NCAA women’s final, superstar Caitlin Clark’s Iowa Hawkeyes faced an undefeated South Carolina team. 

That drama helped it break the record for the most bet-on women’s sporting event ever, plus plenty of promotion.

“The big sportsbooks were putting out prop bets, so you could bet on over-unders, on player totals, whether it be points, rebounds, things like that,” said Gambling.com’s Christopher Boan.

Boan said those bets are an indicator of the increasing value sports betting companies see in women’s college basketball and women’s sports more broadly. 

“Because that’s where the growth is,” he said. “There’s only so many more NFL bettors you can get, only so many more MLB bettors that you can get, whereas there’s a lot more people out there who are maybe going to put a first-time bet on the Phoenix Mercury to win a WNBA title.”

That means there’s been healthy growth, but you’ll still have a harder time finding legal opportunities to wager on your favorite women athletes and teams, especially outside of high-profile tournaments and championship games, said Victor Matheson, an economist at the College of the Holy Cross.

“Those you’re not going to see the same level of participation among the big sports books for the men vs. the women,” he said.

Alicia Jessop, an expert on the business of sports at Pepperdine University, said it’s “a huge missed opportunity” and that there’s a marketing gap at play. 

“Very likely if you live in the United States, you’ve seen a commercial for a sportsbook,” she said. “And I’m willing to bet you that that advertisement featured a male athlete.”

Jessop said companies willing to make bolder investments in reaching women’s sports fans could see a big return. 

Additionally, for growing leagues, sports wagering can be a tool to attract more eyeballs, said Meghan Chayka with the sports data analytics firm Stathletes. 

“If you made a small wager on a game, you’re far more likely to return in the fourth quarter even in a blowout versus an average fan that just flicks their TV off,” Chayka said.  

More viewers mean more ad and sponsorship dollars and lucrative deals for players. However, Alicia Jessop at Pepperdine said high stakes can also increase bad fan behavior, like player harassment. 

As betting markets grow, she says leagues have a responsibility to protect athletes.