Quote from endsongs:
I hope people realize there will be massive exceptions to this. Both GS and JPM have HFT scalping businesses that would be rendered highly unprofitable. I'm sure other politically connected traders/investment banks will gain exemptions from this too. Also, 0.5% roundtrip is way too much to charge. I'm thriiled because I recently came up with a day trading strat I'm currently trading with real $ that averages ~ 0.6% per trade. (I've not posted about it on ET and I probably won't as positng results here seems to bring me bad luck). But, in my case, 0.5% will end the profitability for this strat unless there Is a market, like FX, that is not taxed. So, I think the tax would be less that 0.5% roundtrip.
anybody with exchange status memberships would be exempt, you just have to join a firm with that status instead of trading on your own.