The Zero Axis of Payment for Order Flow

The SEC determined estimated that for the exchanges, you take out the auction stuff for intraday trading. The net capture rate is two mills, which basically means that if you're charging the maximum of 30 mills, 30 cents for 100 shares, and then rebating all but two mills of that, you're transferring over 90% of the total incoming revenue to liquidity providers on the other side. And that's pretty heavily concentrated among a relatively few firms too.