Quote from atticus:
VIX traded 10-30 in 2007. They're Euro-convention, so while they can't be exercised, they are marked to market.
Binaries are defined risk, so he essentially sold a "50/100" put. One would have to assume it's trading North of 95/100.
His risk should be limited to something approaching the $4.6B liability per the AR. So he's lost nearly $4.6B based on a "50/100" assumption.
If it's trading north of 95, perhaps he should do a Lenny Dykstra and just keep doubling down until he's proven right.

Seriously, I still do not understand the timing. Not that anyone knew the cash S&P would be trading at the Antichrist level, but if most stocks are in his view "overpriced", which has been his view for most of the last, what, twenty years, then why make a bullish bet then (and not even hedge)?
Better to have done it when "Mr Market",as he likes to call it, is in a bad mood, like right now.