Dr J sold Mercury for something approaching $50MM. His brother pocketed $6MM from the deal, ostensibly Jon pocketing the rest. I was 22 at the time and working at HTC when Jon lost something like $4MM in Genentech short vol. I was in RealTick's office when another local in the office told me the story. He was laughing and stated that it happens too often with Dr J.
Mercury had some decent exposure and high-volume posts which led to overpaying for his operation, despite Jon almost bankrupting the company on various occasions.
Edit: It was pharma/biotech. Not certain of the ticker, but IIRC it was Genentech.