I don't think Bitcoin really have scary tax implications if you're an exchange -- you're moving Bitcoin in and out of your wallets so often you can just choose the most advantageous coins. An exchange is necessarily going to have better record keeping than an individual because the executives of the exchange can go to jail if things go wrong and proper safeguards weren't in place.
This is really no different than how most commercial banks work -- your balance is used to buy stocks, bonds and financial derivatives (obviously subject to certain portfolio risk management requirements). It used to be illegal to do this with non-government securities (aka bonds) until Glass-Steagall was repealed, but now everyone does it. They trade these securities on a regular basis, and then at the end of the quarter they book capital gains and losses.
This is really no different than how most commercial banks work -- your balance is used to buy stocks, bonds and financial derivatives (obviously subject to certain portfolio risk management requirements). It used to be illegal to do this with non-government securities (aka bonds) until Glass-Steagall was repealed, but now everyone does it. They trade these securities on a regular basis, and then at the end of the quarter they book capital gains and losses.