What Happened to Online Sports Betting (OSB)?

Online Sports Betting (OSB) has undergone a dramatic transformation, evolving from a niche, often illicit activity into a mainstream, regulated industry. Historically, sports betting in the United States was largely restricted by the Professional and Amateur Sports Protection Act (PASPA) of 1992, which effectively outlawed sports wagering nationwide, with limited exceptions. This federal ban, however, did little to curb demand, leading to a massive unregulated market handled by offshore bookmakers and illegal operations.

The pivotal moment arrived on May 14, 2018, when the U.S. Supreme Court, in Murphy v. National Collegiate Athletic Association, declared PASPA unconstitutional. The Court ruled that PASPA violated the Tenth Amendment's 'anti-commandeering principle,' which prevents Congress from compelling states to legislate as it dictates. This landmark decision empowered individual states to decide on the legality of sports betting within their borders, unleashing a cascade of legislative activity.

The repeal of PASPA immediately spurred states to action, eager to tap into new tax revenue streams and regulate an existing underground market. New Jersey, a key litigant in the Supreme Court case, was among the first to launch, with online sports betting going live in August 2018. This rapid adoption by states, driven by both economic incentives and public demand, quickly reshaped the landscape. By May 2026, 39 states and Washington D.C. had legalized some form of sports betting, with 30 states offering legal online sports betting via smartphone apps or websites. Major operators like DraftKings, FanDuel, BetMGM, and Caesars Sportsbook quickly established dominance, often through aggressive marketing and promotional offers.

As of August 2026, the online sports betting market continues its robust growth. The global online gambling market, with sports betting accounting for over 50% of revenue, is valued at approximately $101.45 billion in 2026, projected to reach $168.71 billion by 2031. In the U.S. alone, Americans are projected to wager between $160 billion and $170 billion legally in 2025, with online bets accounting for a vast majority. The industry is increasingly characterized by technological sophistication, including the integration of AI and machine learning for personalized recommendations, real-time odds, and enhanced fraud detection. Mobile and in-play betting dominate, with mobile devices generating over 80% of online gambling revenue in the U.S. and live betting accounting for 53.40% of all wagering activity in 2026. Responsible gambling initiatives are also gaining prominence, with some states introducing bills to tighten regulations on promotions and implement tools for player protection. Legislative efforts continue in 2026, with states like Nebraska, Alabama, and Georgia actively considering or pushing for online sports betting expansion. California, however, banned sweepstakes sites operating with dual virtual currency models as of January 2026. The industry is shifting from rapid expansion to consolidation and optimization, with a focus on technology, data efficiency, and customer retention.