There are myriad ways in which J.P. Morgan’s “hedge” could be securities fraud. Here's an easy one...
At the most basic level, the fact that JPMorgan made (giving the bank the benefit of the doubt) such a massive risk management error may, in and of itself, be proof of fraud. Why? Because courts have held that companies are liable under the securities laws for misrepresenting “qualities” like risk management commitment/capability.
Certainly, JPMorgan has gotten a lot of mileage from touting its superior approach to risk management.
If, in fact, JPMorgan turned a blind eye to the risks responsible for the debacle, or otherwise acted inconsistently with its stated approach to risk management, then that is fraud.