Harry Markopolos spotted Bernard Madoff's $65bn Ponzi scheme years before it imploded.
source https://www.google.com/url?rct=j&sa=t&url=https://www.hbsslaw.com/blog/hagens-berman-blog/whistleblower/whistleblower-news-madooff-ge-opioids-cryptocurrency-kickbacks&ct=ga&cd=CAIyGmM2Nzk3ODA2ZWViNjVjODI6Y29tOmVuOlVT&usg=AFQjCNGMdsC9zlad15iJCNOV8G4a5pCg9w