[physguy1123]

It might simply just be that's the terms that Robinhood reached with the firms? Paying 0.2c/share and giving 0.2c/share price improvement is fairly similar from the perspective of a market maker as just paying 0.4c/share, and Robinhood might be funding themselves by having firms only compete on payment for orders and not on price improvement.

On a more meta level, my firm suspects that Citadel is trying very hard to price other players out of the market even if it's at the cost of their current profitability, so they might be driving up the terms of newly minted deals. I don't work on the retail desk so I don't know.