When the Supreme Court struck down the federal prohibition on sports gambling in May 2018, it did more than change the law: it opened an untapped market that states, casino operators and tech firms rushed to exploit. The decision in Murphy v. NCAA effectively returned authority over sports betting to the states, and within months legislatures and voters moved to authorize wagers that had been illegal for a quarter of a century.

The economic consequences have been profound. Legal sports betting, once limited to Nevada and a handful of tribal venues, has expanded to more than 35 states and the District of Columbia, with retail and—crucially—mobile wagering becoming dominant. Industry groups and state reports show betting handle surged from near-zero outside Nevada in 2018 to levels measured in the low hundreds of billions of dollars annually within a few years, while operator receipts and taxable revenue climbed into the billions. States have collected "billions" in taxes since legalization, helping fund education, infrastructure and regulatory programs, according to aggregated state data.

Market winners emerged quickly. Legacy casino companies used sportsbooks to diversify declining brick-and-mortar revenues, while digital-native firms such as major fantasy and betting platforms scaled rapidly through mobile apps, marketing partnerships and aggressive customer acquisition spending. Mergers and public listings followed: sportsbook operators and platform providers attracted investor capital and strategic deals that reshaped the gambling and media landscape. Professional leagues and broadcasters, which once opposed the repeal, have embraced betting through data licensing and partnerships, turning live sports into a continual source of engagement and betting content.

But the growth has been uneven and complicated. State-by-state regulation has produced a patchwork of tax regimes, licensing requirements and consumer protections. Tax rates and fee structures vary widely, with some states prioritizing revenue and others emphasizing industry development. That fragmentation has encouraged cross-border marketing and complex compliance strategies, raising questions about regulatory arbitrage and enforcement. Public-health advocates and some lawmakers warn about rising problem gambling and the social costs of expanded access, and regulators are still building out responsible-gambling programs and data-sharing regimes.

Long-term trends point to further consolidation and technological innovation. Mobile betting, live in-game wagering and real-time data products are likely to capture larger shares of handle, while advertising and sponsorships tie betting more closely to sports media. The industry’s sizable growth has prompted renewed debate in Congress about whether to adopt federal standards for consumer protection, data integrity and advertising—an argument that could intensify as national elections and lobbying dollars converge on the issue.

The 2018 ruling did not mandate a single model; instead it created a competitive experiment across dozens of jurisdictions. For policymakers, investors and consumers, the test now is balancing revenue generation and market dynamism against public-health safeguards and regulatory coherence. The economic stakes are large, and five years after the court’s decision, sports betting has moved from the margins to the mainstream of America’s gambling and entertainment economy.