Scouring digital currency exchanges for trends, Singapore-based cryptocurrency analyst Patrick Tan began to peer into an underground world of payments and wallets where Asia’s scammers, drug dealers, hackers and other criminals clean their illicit earnings. The general counsel at Singapore-based crypto intelligence firm Chain Argos’ initial brief was to help investors looking for smart digital bets to cut through the influencer-led hype around cryptocurrencies. But as his analysis deepened, he started to investigate cyber fraud cases on behalf of victims from as far apart as the United States and China, segueing into a parallel money system where cash from so-called “pig butchering” scams is washed and moved through multiple digital wallets, often linked to other criminal organizations.