Illegal Online Gambling Market Hits $5.9 Trillion Worldwide in 2025

The global illegal online gambling market reached an estimated $5.9 trillion in 2025, according to a new report from Gaming Compliance International (GCI). The figure is up 4% from 2024 and continues the strong growth seen in recent years.

The report focused only on online gambling and did not include offline gambling businesses. GCI counted operators that actively accepted payments and targeted local users.

According to the study, unregulated gambling now makes up around 78% of the global online gambling market, while licensed operators account for 22%. The report covered sports betting, online casinos, poker, crypto gambling, lotteries, and prediction markets outside the US.

Researchers said many users struggle to tell the difference between licensed and illegal gambling websites online. GCI described this as a “white noise marketplace,” where unregulated operators blend in with legal brands.

The company also warned that illegal gambling ads are spreading through sports streaming websites. More than 80% of illegal sports streams in the US and UK reportedly featured unregulated gambling ads during major events in 2024 and 2025.

Prediction markets and crypto gambling were also named as major drivers behind market growth. Brazil recently blocked several prediction market platforms, while Australia and the UK are discussing stricter gambling advertising rules.

GCI said regulators are now dealing with a massive global industry operating outside official control.