[samolang]

> What a broker does has nothing to do with how market orders work.

A market order submitted to a single exchange isn't the same as a "market order" submitted to e.g. Fidelity.com. He's talking about the latter.

[physguy1123]

Then this whole discussion is nonsensical since in almost all cases retail orders are directly filled by wholesale market makers and don't ever land on the exchanges (and don't see any 'frontrunning' as a result).

[samolang]

Sure. All I was saying is that it's theoretically possible for a market order that a customer submits online to be front-run (as opposed to a market order submitted to a single exchange). No clue how often it happens in practice.