Online betting is off to the races - and this summer the adoption curve started looking like a hockey stick.

According to a new analysis by Bank of America - which can see every ACH, debit and credit card payment its customers make to and from sportsbooks, horse-racing platforms and prediction markets their own customers make: 

Roughly 5% of BofA customers sent money to an online betting platform in July.

The number of online bettors is up 40% since the start of the year.

The number of first-time bettors in June and July was more than triple the January level.

The bank credits the summer spike to the World Cup and "promotions and buzz" around prediction markets, and fair enough: every adoption curve has a catalyst. What matters is what the base looks like once the catalyst passes, and here the seasonal pattern is instructive. First-time users jump with every major sports season, and the 2025 football season - which the bank defines as September through February, so it sweeps in the NFL, college ball and most of the NBA and NHL - produced 22% more first-timers than the year before. Each season enrolls a larger freshman class. The class that enrolled this summer was three times the size of January's, and it arrived right before the busiest stretch of the calendar.

Nor is this something people try once and forget. Per a CivicScience survey cited in the note, 34% of online sports bettors wager weekly and 23% bet daily; fewer than one in five are the several-times-a-year Super Bowl crowd. That is the engagement profile of a social app, not a lottery ticket.