macrocephalopod

Document means to provide evidence, not make a simple assertion. Provide the tick data and the trades that *show* it.

i would never betray my clients trust by posting their order flow

Nice answer but I'm am not asking *you* specifically. If company XYZ announces results, and claims that they are responsible for $1 billion in "price improvements" the burden of proof is on them to prove it they wish this to be considered any more than marketing talk.

They kind of can’t win with this. Plenty of companies do post it. I just googled and found an article where two different firms mentioned their px improvement, but once they do that, the argument starts in about how moving those orders off exchange = not real “improvement”

precisely. what if all the orders were lit?!? then there could never be price improvement? i dont care about slippage or any of that nonsense

It’s just theoretical discussion, we obviously can’t know what would happen if we moved every single order to a lit exchange and maybe it would be worse who knows

just a series of moving goalposts with no one wanting to suggest real changes when they could just quietly do what they want and see if it makes them money too

I mean sure, you have to invoke counterfactuals and talk about opportunity costs and it gets a bit abstract but otoh ... opportunity costs are real? I don’t have an easy answer to the question “would markets be better if we put everything on a single l exchange” but it seems like