Harry Markopolos
Madoff whistleblower, author of No One Would Listen: A True Financial Thriller and these days a contrarian — yay! — hedge fund manager, known for having a pop at the likes of GE. Ironically, no-one seems to be listening. Which in itself is pretty amazing, given his track record.
Here is Harry Markopolos’ 18 page submission about Madoff to the SEC from November 2005 that says “Madoff Securities is the world’s largest Ponzi scheme”.