Has anyone figured our how Epstein made his money?

His Financial Trust asset management company seems to have had no clients and generated relatively little (declared) income. His real estate holdings all seem to be his own property. He come from a middle-class background and did not inherit his wealth.

This press seems annoyingly uninterested in this question and usually just refers to him as a "financier" without being able to point to anything he's actually financed.