Illegal online gambling generated an estimated $5.9 trillion in global wagering value in 2025, according to a new report from Gaming Compliance International (GCI), with analysts describing the underground market as effectively the world’s third-largest economy after the United States and China.
The report, titled “GCI Online Gaming 2025: Global,” said the figure marks a 4% increase from the estimated $5.7 trillion recorded in 2024 and continues a sharp upward trend from $5.1 trillion in 2023. Researchers focused exclusively on online gambling activity and excluded land-based operations from the analysis.
According to GCI, unregulated operators now account for around 78% of global online gambling gross gaming revenue, while regulated companies represent only 22% of the market. The study covered offshore sportsbooks, online casinos, poker platforms, crypto gambling sites, lotteries, and prediction markets operating without licenses in the jurisdictions they target.
Matt Holt, CEO of Gaming Compliance International, warned that regulators are no longer dealing with a fringe issue. He said the majority of online gambling activity is now taking place outside regulated systems, creating major risks for consumers and governments alike.
The report also introduced what GCI called a “three-sector gaming marketplace.” Alongside regulated and unregulated gambling, researchers identified a fast-growing third category described as “unacknowledged gambling.” This includes products such as sweepstakes casinos, skins trading, social casinos, and prediction markets that mimic gambling mechanics while operating in regulatory grey areas.
Ismail Vali, GCI’s president, said consumers increasingly struggle to distinguish between legal and illegal platforms because all services appear together online and compete for the same audience. He described the environment as a “White Noise Marketplace,” where regulated and unregulated operators become almost indistinguishable to users.
Researchers also linked the growth of illegal gambling to crypto-based betting products, illegal sports streams, and loosely regulated prediction markets. GCI claimed that gambling advertisements appeared on more than 80% of illegal sports streaming services monitored in the United States and United Kingdom during 2024 and 2025.
The findings arrive as several countries intensify efforts to combat offshore gambling. In the UK, H2 Capital recently estimated that the offshore gambling market reached £16.6 billion in 2025, up from £5 billion in 2019. Meanwhile, Brazil has already blocked dozens of prediction market platforms after declaring them illegal, while Australia has introduced tighter advertising restrictions tied to gambling content.
Industry experts warned that excessive restrictions on licensed operators could unintentionally drive more consumers toward black-market alternatives offering fewer compliance checks, bigger bonuses, and unrestricted betting access. Regulators and gambling companies are now calling for stronger international cooperation, payment blocking measures, and faster enforcement tools to slow the expansion of illegal gambling networks.