I'm amazed at the lack of common sense shown by politicians and regulators regarding the JPM trading loss. This is a company that has a stellar track record and it is absurd to think that they will never lose money when trading. Company's make mistakes and can't just always print out money. Wouldn't that be a bigger concern if companies did nothing but make money through trading as it is a zero sum game? I can imagine the conspiracy theories that such a situation would rightfully bring up as people would think that the game is rigged. I do believe there should be more transparency into the trading books and all swaps should be on exchanges. While banks won't like this they will eventually, as their current valuations are reflective of the ambiguity that market participants feel when evaluating the financials of banks, and more transparency will likely lead to higher valuations. Proprietary trading will have a much smaller impact in the future for banks so more transparency would be much more of a positive than a negative.
Disclosure: I am long JPM.