Global unregulated online gambling wagering volume reached $5.9 trillion in 2025, with illegal operators accounting for an estimated 78% of worldwide online gaming gross gaming revenue, according to a report released by Gaming Compliance International.
The figure marked a 4% increase from $5.7 trillion in 2024 and extended growth from $5.1 trillion in 2023, according to the report, which focused exclusively on online gambling and excluded retail betting shops and land-based casinos.
The study defined unregulated gambling as unlicensed products marketed to local users, including sports betting, online casinos, poker, lotteries, crypto gambling, and prediction markets. GCI used automated surveillance systems alongside manual analysis to estimate betting turnover and gross gaming revenue.
“The scale of the unregulated online gambling sector is now undeniable,” GCI Chief Executive Matt Holt said. “At $5.9 trillion in wagering value, unregulated online gambling is one of the largest economic systems in the world, operating largely outside regulatory oversight."
The report introduced a three-part market structure comprising regulated, unregulated, and “unacknowledged” segments. The latter category includes social casinos, sweepstakes, skins trading, TikTok contests, and prediction markets, which the report said often replicate gambling mechanics without being formally classified as gambling.
GCI said prediction markets are regulated as financial products by the Commodity Futures Trading Commission in the United States, but were counted as unregulated gambling outside the country.
GCI President Ismail Vali said the boundaries between the categories had become increasingly blurred for consumers.
“In a world where you can bet on anything, consumers are increasingly betting on everything. This is the gamification of everything,” Vali said. “The audience does not distinguish between these sectors. They experience one marketplace, where everything is accessible, and everything competes equally.”
GCI estimated around $3.1 billion in prediction-market trading volume tied to the Super Bowl and related events earlier this year.
The report found that prediction platforms are 0.2 percent of legal sports betting profitability inside the US. On the unregulated side, prediction-style products are already 8.7 percent of unregulated online sportsbook revenue.
GCI also warned that prediction markets and illegal sports streaming could accelerate black-market gambling growth in 2026. According to the firm, unregulated gambling advertisements appeared on more than 80% of illegal sports streams in the United States and Britain during 2024 and 2025.
Prediction markets have also drawn regulatory scrutiny outside the US. Brazil recently blocked 28 prediction-market platforms after declaring prediction markets illegal, while in the opposite direction, Gibraltar licensed its first regulated prediction-market operator earlier this year.
The findings also come as governments in Australia and Britain move toward tighter gambling advertising restrictions. Separate research published by H2 Gambling Capital estimated the British offshore gambling market reached 16.6 billion pounds ($22 billion) in 2025, up from 5 billion pounds ($6.6 billion) in 2019.
Holt said regulators are facing a growing challenge as gambling activity increasingly shifts beyond licensed systems.
“What this report makes clear is that regulators are not facing a marginal challenge, but a dominant one,” Holt said. “The majority of activity is occurring beyond the regulated perimeter.”