Basketball fans across the country are gearing up for the start of March Madness — and for many, that will mean making big bets on their teams.

Why it matters: The American Gaming Association estimates that $2.72 billion worth of legal bets will be placed on this year's NCAA tournaments.

• March Madness is "the largest betting event in the U.S.," Cait DeBaun, vice president of strategic communications and responsibility at AGA, told Axios.
• Sports betting has been on the rise in recent years as more states have legalized it.
• Currently, 38 states and Washington, D.C. have some form of legal sports betting, per the AGA.

By the numbers: The $2.72 billion estimate is around 2.2% of the total number of legal sports bets placed last year, the AGA wrote in a post on X.

• A total of $121 billion in bets were placed on all sports in 2023, a 30% increase from 2022, DeBaun said.

The big picture: The NCAA on Sunday revealed the top seeds for both the men's and women's tournaments.

• Leading the men's slots are UConn, Purdue, Houston and North Carolina.
• On the women's side, South Carolina, Iowa, USC and Texas are top of the pack.

Zoom in: Axios Local is keeping close tabs on the tournaments and several cities have their own bracket challenges with ESPN.

Follow along here:

• Columbus
• Indianapolis
• Cleveland
• Denver
• Salt Lake City
• Nashville
• Chicago
• Phoenix
• San Diego