South Korean retail investors lost approximately ₩336 billion, or about $250 million to $251 million, to stock-related fraud in the first six months of 2026. Police investigated 3,506 cases linked to stock recommendation chatrooms, up 4.1% from a year earlier, while losses rose 19.8%. The KOSPI posted the strongest gains among major global stock indexes during the first half before falling as much as 44% from its June 19 peak. Fraudsters exploited fear of missing out during the rally and uncertainty after the decline by moving victims from social media and video platforms into private chatrooms, fake trading applications and bank transfers. Tactics included impersonating securities firm employees and financial influencers, charging large fees for stock tips and soliciting funds for supposed portfolio management. Seoul police said 10 people were arrested in a Cambodia-based operation accused of defrauding 59 South Koreans of approximately ₩9.9 billion, or about $7.3 million. Authorities, banks and online platforms are strengthening detection, but the Financial Supervisory Service said it does not maintain data on illegal stock recommendation chatrooms and offered no comment on new investor-protection measures.