Read a bit and wasn't sure of the exact nature of the 700k loss, but if he somehow got access to all that credit without the assets to back it it, it would seem like people can form a pact, where person A gets credit and bets X on a thing, person B bets the counterparty -X, have X be comically large, one person gets the payoff while the other declares bankrupcty, and basically "gain X/2 for enduring bankruptcy". (We can have some variation to sweeten the pot, where the losing person gains X/2+C, winner gains X/2-C, where C= some additional money to deal with bankruptcy hassles.)

Presumably this doesn't actually happen since it's doable, so I'd be curious what -700k losses practically means.