I use Interactive Brokers, they don't sell flow, unless you have a lite account, there is a list here https://www.warriortrading.com/direct-access-brokers/
I hate their options port. It's so inconsistent. For example if I buy a strangle leg by leg, it'll show as -PUT -CALL but if I buy them together, it'll see it as Strangle Put/Call. It gets very confusing when you have a lot of positions.
Bumping to see if anyone has any intel on this...I'm very interested in custom margin offset services. Is this a standard feature of prime brokerage? Are there any other brokerages or 3rd-party services that -- for either a fee, or for accounts of a certain size -- will override the typical margin settings for an account (if a bespoke analysis assesses that the overall portfolio has lower risk than the default margin settings would require?)
Would you benefit on a free broker with liquid stocks? I can't imagine you being too hurt even with volume when you buy stuff like SPY. They'll front run you for a fraction of a cent per share which in total would be cheaper than if they charged you $1 for a transaction. Paid 9k for transactions last year and all my transactions were only $1 each! If i had a broker like Robinhood, would I have paid less? I don't know because it's impossible to compare 9k worth of transactions charged on the spread level.
Robinhood is good only for beginners. They have a very limited number of assets that one can trade, so that’s a big no for me.