There are other postings here about KCG. many brokers and carriers who did business with Quebecor wrold between November and when QW was grabted protection from creditors (some in Feb) never did and probably never will get paid by QW, so don't rely on the trust account provision in the HTA as no trust was created, i.e. the only have to put money in a trust account from the time the customer paid then till they paid you.
However, KCG as I have stated before , is not an incorporated company, and therefore the principal (the nephew) is also personally liable for the debt.