H2 data: March Madness handle to decline in 2025

The March Madness NCAA men’s and women’s basketball first round kicked off last week, signalling the start of the most bet-on event in the US sporting calendar. Although the Super Bowl remains the one-off game receiving the most bets across US sports, with an estimated $1.6 billion bet on Super Bowl LIX, basketball remains over a third of overall US betting handle.

This tournament typically presents operators with a great opportunity to grow their customer base and give handle a welcome boost for the three-week period.  

H2 Gambling Capital has estimated a total of 169 million bets will be placed during March Madness this year, resulting in handle for the event reaching $2.9 billion. This implies a slight decline of 1.5% from the prior year’s tournament, following a number of years of consistent growth.

A slowdown in 2025’s event is also estimated, on the back of slowing handle growth in the past few months. This is coupled with the fact there have been no new online sports betting state launches since the last tournament, which was boosted by the launch of North Carolina.

The “Caitlin Clark effect” also boosted 2024’s handle. We also highlighted that these estimates do not include bets placed on prediction or sweepstakes markets, which could eat into the official regulated wagering market.

March Madness hold rates lower than other sports

March Madness typically brings lower hold rates than that of professional sports. This is due, in part, to a lower percentage of bets being same-game parlays, as a result of individual players being less well known.

This can make player props less popular. This lower hold rate can be seen in Vermont last year, where a hold rate of just 1.14% was recorded for March Madness, compared to an 11.03% hold rate across all sports betting for the year.  

H2 has estimated hold rate for this season’s tournament will reach 7.8%, an increase from last year’s estimated 7.5%. When considering our handle estimates, this hold rate implies GGR (gross gambling revenue) of $223 million, up $7 million on the prior year’s estimate. This is due to hold margin improvements offsetting the slight drop in handle.      

Operators will be hoping for an improved hold rate after a difficult NFL regular season that brought historically low hold margins. However, 2025 is believed to have had a more positive start following a very good Super Bowl performance for operators. This was thanks to many of the most popular player props going their way.

In regard to March Madness, with the lower percentage of parlays, operators’ hold margin is likely to be impacted more by the outcomes of the matchups, with operators cheering on the underdogs to drive a higher margin.  

Who’s the favourite this March Madness?

This season’s men’s competition sees the four number one seeds enter as clear favourites, with the Duke Blue Devils just edging out the others to be tournament favourites at +300. The team is led by star player and number one overall recruit, Cooper Flagg, who is expected to be available for Duke’s first round game following an ankle sprain.

As for the women’s tournament, the South Carolina Gamecocks are favourites to retain their title at +240, marginally ahead of the UConn Huskies at +260. The women’s tournament had a big boost in popularity last season and accounted for 12.5% of 2024 March Madness handle in Vermont.

Basketball accounts for over a third of US handle

Basketball remains the most popular sport for bettors in the US, accounting for 32% of handle in the US sports betting market in 2024. H2 has estimated c16% of total basketball handle is generated from NCAA college basketball rather than the NBA/WNBA professional leagues. 

As with all sports, basketball is highly seasonal, with peak handle generated in the first quarter of the year, peaking in March with the March Madness competition. 

As demonstrated below, total US betting handle growth has been slowing over the past few months. Growth in the last three months of 2024 was 23%, in comparison to 43% in the prior year period. In December, in particular, it only increased 14%, compared to 52% growth in December 2023. 

Total regulated US sports betting handle increased by 39% year on year to $14.6 billion. H2 forecasted continued growth in 2025, albeit at a lower rate, with 2025 handle forecast to grow at c25% year on year to around $18 billion.

This will be driven in part by an assumed launch in Nebraska later in the year, along with Missouri estimated to come online in Q4, which will boost the organic same-state market growth.