Paying that much in commission likely means he deals directly with liquidity providers so the most he is paying is $20 round trip per million, so that could imply that he is taking a position of 50mil. To be able to trade 50mil, one would need 1mil here in the us or 500k abroad and that's assuming Max leverage. Of course he could be paying higher commission, which would make him as dumb as someone who would brag about paying a grand just in commission.