A Ponzi scheme is a fraudulent investment operation. For example, when you owe money & you don't pay early enough. Let's say you borrow money from your friend & it's thousand dollars & then you don't pay early enough
The way Bernie Madoff was able to keep this scheme go, for so long was because the way he acted with the people around him. He acted like everything was okay, as if he never did anything. Everyone thought he was a nice caring guy, but in reality he was staling money from everyone. Plus, he didn't really tell anyone how the money was really working around
A "Ponzi Scheme" person acts different than any regular human out there. They will be your 'best friend' & they're going to ask you to borrow money & not give you, your money back on time. They will "care" for what happens to you or your family. Act a totally other person. They will want to know everything about how your money is going.
The SEC didn't do anything after Madoff's arrest because at that time they didn't really get the math about how the money works. Since they didn't have anything to argue with, they decided not to say or do anything after Madoff's arrest. If they did a bunch of people would've been against them, because they had realize that the money was getting lower because Madoff was stealing away from people's money they were making.
I feel that Madoff did this scheme ether to get attention or he just didn't feel bad for the people that were actually working hard to get there money. Or probably didn't have enough money & decided to do the scheme to be rich. There's a lot of probably reasons to why he did what he did.