The tick size changes are interesting as well in the context of auctions. If a claim is "you can't have an auction with sub-penny pricing so there's no improvement", well then make the tick size smaller.
That’s what PFOF has brought to retail investors. It’s not like retail investors was ever put onto the public exchanges prior to robinhood and PFOF, they were sent to dark pools for institutional investors to trade against but retail investor never got the benefit.
The payments per share tend to be extremely small - on most symbols the broker isn't making $5-10 per trade from the MM, for reasonably sized trades.
Even if payment for flow was costing you that much, paying for an order vs giving more price improvement are indistinguishable. Payment for order flow just means that price improvement definitely goes to the broker instead of back to you.
Are you saying that if makers' profitability at lit venues was greatly improved, they wouldn't compete to offer tighter spreads at all?
> The customers think they have no cause for complaint, because they did better than the NBBO. The whole thing is an institutional equivalent of retail payment for order flow: The partner firms fill the customers at a better price than the NBBO, make some profit for themselves, and kick back some of it to the broker (Coda).
https://www.bloomberg.com/news/newsletters/2021-09-23/money-...