It's actually based on information made available by the Company at the time you bought. If the company was puffing ( a nice word for lying)--- and with the rate of fraudulent PR's from thighs Company--that's not a problem,-- then you are a candidate for rescission.
It works best as a class, and I think you would find a number of others willing to file with you.
News 
Market Data 
Discover 
