You're obviously a troll. You aren't seriously trying to claim that Wall Street firms don't engage in deception are you?
If I bring up examples they will be flawed because they are populist and because I don't understand banking as well as you do.
The banking system is flawless but you have to be a banker to understand this.
You did however did claim that any hint of deception would destroy their business and that therefore deception is not happening.
I think your claim is absurd and does nothing to help the financial system become more effective for society at large.