Russell R Wasendorf Sr, founder of PFG, attempted suicide early this week after he was charged with running a $200m futures fraud.
The fast-moving case raises new doubts about the supervision of the futures trading industry in the aftermath of the MF Global debacle that left investors $1.6bn out of pocket.
After MF Global's collapse, Russ Wasendorf Jr, Mr Wasendorf's son and Peregrine's president, wrote on their website of "the sanctity of customer-segregated account balances".
The Commodity Futures Trading Commission said Peregrine and Wasendorf, a fixture of the Chicago trading community, kept only $5.1m in a customer account they falsely said held more than $200m.
Like MF Global's Corzine, PFG founder Wasendorf Sr, 64, was seen as a man of sterling repute and impeccable credentials.
"[He] seemed like a boy scout," said a broker who had extensive dealings with PFG and who requested anonymity. "They were spending a lot of money on pre-education for their customers, and Senior seemed like the salt of the earth."
The disclosure came after owner Wasendorf, a 40-year veteran of futures markets, was found in his car near the company's new headquarters in Cedar Falls, Iowa, having apparently attempted suicide.
He left a note "saying he had done something wrong", the company said later. He is in critical condition at the University of Iowa Hospitals, according to local news reports.