The world's biggest fraudster (allegedly?) is George Madoff who appears to have run a $50 Billion pyramid* scheme. It is a mystery why anyone was surprised, the clue is in the name, George Madoff made off with the money.
These investors are the sort of people who were amazed when it turned out that Cruella De Vil was a villain.
* The word pyramid for some reason made me think of the old confectionary item the "Pyramint" for the first time in about 20 years. This inspired me to google it to see if they were still being made. They aren't but the Wikipedia page on the subject is very helpful noting that: