A free market also implies some transparency does it not? If it's crystal clear what is being bought & sold, then everyone can make informed decisions and take

A free market also implies some transparency does it not? If it's crystal clear what is being bought & sold, then everyone can make informed decisions and take their gains/losses honestly. When things like derivatives are created specifically to obscure the product and mislead potential buyers, then is it truly a free market? Shouldn't the government's roll be oversight (aka interference) if deception is creating a clear advantage for one party in the transaction? Your premise of mutual gain falls short in these cases.