> they aim to make maybe 5 cents this way on a $480 stock, mostly holding for less than a few seconds, on millions of trades an hour > MM are ultimately a good

> they aim to make maybe 5 cents this way on a $480 stock, mostly holding for less than a few seconds, on millions of trades an hour > MM are ultimately a good thing because they provide liquidity. there is always a person willing to take the other side of a trade when you click At the end of the day, it's not clear where the liquidity is going to come from unless there are non-middlemen buyers on the other side. Reducing typical spread and commission fees seems like a more realistic benefit.