Someone Must Have Benefitted from Societe Generale's Trading Loss

Not necessarily.

Consider what what has happened with the big drop in the DOW or S&P lately. There has been a massive loss in value for almost everyone of trillions of bucks. A few may have profited, most obvious short sellers, but that doesnt affect the nett loss of trillions of bucks overall. That loss didnt end up in anyone's pocket.

You'd be wrong. You're ignoring the nett loss in the value of the market.

It isnt.

In theory those who shorted the market. But that doesnt mean that they made a nett profit themselves, most of them just didnt lose as much as the worst losers did.

That isnt what happened either. What actually happened is that it became clear that the market had dropped so substantially that it was possible for SG to lose that much money when it did, and that made plenty wonder how many other operations had lost even more money, but just hadnt fessed up to losing that yet.

Many of the operations that did make some money out of SG's fiasco arent even listed companys.

Because there was a massive nett loss in value of listed securitys.

Just how many of you are there between those ears ?

Corse there was a nett loss in the value of listed securitys.

Nope, because there was a massive nett loss in the value of listed securitys.

Nope, just not as great as what SG lost.

You made a good point. However, even a stock trader can trade a share of some DOW FUTURES for $5000, which implies that she/he feels that the value of the Dow would be 5000 at some point in the future. Let's assume that the "point in the future" is actually 1 business day. Intuitively, you and I know that there is no way that our Dow Jones, currently at over 8,000 will crash to 5,000.

Therefore, I'd buy the hell out of this FUTURES CONTRACT AND SELL TOMORROW, AND I'D PROFIT THE DIFFERENCE OF OVER $3,000.

If you fill your car's tank of gas with 15 gallons of gas, and the proprietor of that gas station only charged you $0.30, as opposed to $30.00, *YOU* - the CAR OWNER - has profited to the detriment of the gas station.

Particularly if short selling is banned as it is in some markets, there arent necessarily any that make a profit at all, everyone loses, some more than others.

Yes. But if no one chose to do that, there isnt necessarily anyone who profited form the SG loss.

Yes, but in practice futures arent bought like that, so its just an academic possibility.

Futures dont work like that.

Yes, but thats irrelevant to your SG question.