Quote from Occam:
I know you're not asking me, but I'm confident in saying that this is an incredibly comlplex problem. Exchanges are adding ever-more complex (and rapidly changing) pricing schemes and order types in an effort to differentiate themselves in a market where differentiation is getting ever harder, even as volume shrinks and B/D internalization rears its ugly head in defiance of a (haltingly) opposed SEC that wishes otherwise.
I think the investing public would be better off if all venues adopted identical pricing for adding vs. removing liquidity (rather than favoring adders or removers over the other), and B/D internalization and payment-for-order-flow were explicitly banned. But of course many B/D's wouldn't like this (as the present system gives them backdoor income at the expense of their retail clients) .
