There's two sides to every trade though. Somebody wins, somebody loses. The orders on the other exchanges either belong to market makers or other uninformed tra

There's two sides to every trade though. Somebody wins, somebody loses. The orders on the other exchanges either belong to market makers or other uninformed traders. If you structured the market so market makers couldn't see order flow as quickly, they'd charge a larger spread to everybody. Right now they charge a tight spread so long as the incoming order is small because they know at least some of the time they can get out of the way or try to dump their shares when a big order comes in. That's good for the small guy. They wouldn't even be there for the big guy to hit if you changed the rules. Instead the sales trader would only see half the shares at the best price and end up paying multiple ticks just like he does now. If the orders on other exchanges are uninformed slow traders, they're going to lose either way, so we're really arguing over whether the savvy hedge fund or the fast aggressive HFT should get their money. If you're playing the game of making fractions of a tick, you're in the same execution game HFTs are in, so you better get fast.