> As a matter of law, brokers have a duty to seek what’s called “best execution”, meaning they’re required to both shop around for better prices and pass all of

> As a matter of law, brokers have a duty to seek what’s called “best execution”, meaning they’re required to both shop around for better prices and pass all of the price improvement they can find onto their customers. That's the definition of best execution as it applies to undirected orders. But you can also offer your clients direct execution on the exchange, in which case you don't have to (and must not) shop the order around. If RH had done that, they'd be in the clear. Yes, I understand that retail brokers aren't usually in the business of directed orders (because shopping round the orders is in the interest of both them and the client).