Yeah in the press release statement it says it's $88M aggregate loss, so it seems to be net of whatever NAV clients had.$88M is not the net losses (differences between winners and losers)
It is the total of negative balances in IB accounts as a result of trades in these markets.
The losing customers lost a lot more than that for sure.
Any winning accounts are irrelevant to IB.
In the CNBC interview though, TP said his clients held 15% of the open interest and says his clients lost $88M and estimated other brokers to have clients sitting on $500M losses elsewhere. So given that information it would seem $88M could also be the loss from the shorts (88/588 =15%)? I dunno. That or the clients that lost were all small guys, so net of NAV or just summation of losing positions end up being around $88M both ways?
Either way it's interesting if the winners were also at the same brokerage. Basically becomes a redistribution of wealth, kinda. Except it's not the losing traders paying for the winners if they declare insolvency due to catastrophic losses.