I have never seen a explanation for where Epstein's money came from. The majority of his money didn't come from trading. Apparently he got some money and a New York town house from Les Wexner. Wexner claimed that Epstein managed his money. But why anyone with financial sophistication would have Epstein manage their money is difficult to explain.
One explanation for Epstein's money is that rich people paid him for access to young women and that he may have blackmailed those who had sex with underage girls. But this also seems incomplete. For someone with money, access to young women is not difficult and they should not have needed Epstein.
So to me Epstein's wealth remains a mystery.