Sam Bankman-Fried, founder and former CEO of cryptocurrency exchange FTX, is serving 25 years in federal prison for fraud. His company collapsed and went bankrupt in 2022. Investigators found that billions of dollars in customer funds had been borrowed without permission to help shore up Bankman-Fried’s other firm, Alameda Research.

But throughout the last three years, Bankman-Fried has maintained his innocence, and he's filed an appeal. A hearing is scheduled for Nov. 4.

Marketplace’s Nova Safo spoke with Jonathan Jones, a reporter and producer for the investigative podcast “Reveal,” who spent hours talking to the former CEO, FTX insiders and customers.