He lost $20 billion in two days. Banks had no idea how much he owed because he invented a way to hide it. Meet Bill Hwang grew up in South Korea His father was a pastor He moved to the US at 18 with almost nothing and worked his way through UCLA He got a job at Tiger Management, one of the most successful hedge funds in history He was good enough that Julian Robertson, Tiger's legendary founder, helped seed his own fund By 2012 that fund, Tiger Asia Management, had $10 billion under management Then the SEC charged him with insider trading on Chinese bank stocks He paid $44 million to settle and pleaded guilty to wire fraud He was banned from managing outside money He came back as a family office Officially he was just managing his own personal wealth Family offices face almost no disclosure requirements He named the new firm Archegos Greek for "leader" With no outside investors to answer to he had no limits on what he could do He discovered a financial instrument called "a total return swap" A total return swap lets a bank hold the shares while Archegos collects all the gains and losses Because the bank technically owned the shares, Archegos never had to disclose the positions publicly He ran the same strategy simultaneously at Goldman Sachs, Morgan Stanley, Credit Suisse, Nomura, UBS, and Deutsche Bank None of those banks knew what the others were doing None of them knew how leveraged he actually was By early 2021, Archegos had over $100 billion in total stock exposure On leverage of roughly 8 to 1 On March 22, 2021, ViacomCBS announced a stock offering that pushed its share price down Archegos held a massive position in ViacomCBS through swaps at multiple banks simultaneously The price fell Margin calls started arriving Hwang got on a conference call with his prime brokers He told them he could handle it He asked them to hold and not sell Goldman Sachs and Morgan Stanley hung up the phone and started selling immediately Credit Suisse and Nomura held back to give him more time That decision cost them both everything Goldman and Morgan Stanley dumped billions in stock in enormous block trades on Friday March 26 before dawn They limited their losses to almost nothing Credit Suisse lost $5.5 billion Nomura lost $2.85 billion UBS lost $774 million Total bank losses: roughly $10 billion ViacomCBS fell 27% in a single day Discovery fell similarly Hundreds of thousands of retail investors who owned those stocks lost money They had no idea a family office they had never heard of had secretly accumulated 60% of the float using instruments that required no disclosure Hwang had gone from $10 billion to an estimated $36 billion in net worth By the end of March 2021 he had nothing Bloomberg reported it was the fastest personal wealth destruction in history He was arrested in April 2022 Convicted on 10 of 11 counts in July 2024 Sentenced in November 2024 His stated net worth at sentencing: $55 million At his peak he was worth $36 billion The man who was banned from managing outside money because of insider trading Built a $36 billion position managing only his own money And lost it all in 48 hours without anyone knowing he had it