"A few weeks ago we asked a simple question: Why are the same Wall Street banks that lobbied so hard to dilute the passages in the Dodd-Frank financial overhaul bill banning proprietary trading now jettisoning their proprietary trading groups, without so much as a whimper?
The law directs regulators to study the prop trading ban for another 15 months before deciding how to enforce it: why is Wall Street caving now?
The many answers offered by Wall Street insiders in response boil down to a simple sentence: The banks have no intention of ceasing their prop trading. They are merely disguising the activity, by giving it some other name."
I highly recommend Lewis' recent book The Big Short which I wrote previously about here.