Several things you are going to have to look at when proving fraud. What is on the contract, is it legal to produce the document. Is it a lawful document? Having had to sell used Chevy’s for a time in my life, I saw some real crap go down, and yes some salesmen do lie and deceive. But this is what it boils down to in the end, he said/ she said. And judges do not like to determine who said what, when there is no record of the conversation and it all boils down to the contract, every time. If the loan or investments were lawfully executed and on paper, there was no fraud. Most of the time a class action lawsuit is only going to make the lawyer rich and the petitioner poorer and more pissed off.
The argument can be used but if not corroborated through confirmed evidence it would open JPM and their lawyers to a liable and slander suite and could persuade the judge that destruction of a business did take place.