> ...but I’m pretty sure Citadel is not even a major player [in the options market]. A quick sanity check suggests Vanguard[1], Fidelity[2], Schwab[3], and TD

> ...but I’m pretty sure Citadel is not even a major player [in the options market]. A quick sanity check suggests Vanguard[1], Fidelity[2], Schwab[3], and TD Ameritrade[4] disagree with your assertion. [1] https://nms606.karngroup.com/vgrd/606a/2023Q1/588e3c62ff https://nms606.karngroup.com/vgrd/606a/2023Q1/588e3c62ff [2] https://clearingcustody.fidelity.com/trade-execution-quality/sec-rule-606 https://clearingcustody.fidelity.com/trade-execution-quality... [3] https://www.schwab.com/legal/order-routing-1 https://www.schwab.com/legal/order-routing-1 [4] https://www.tdameritrade.com/disclosure.html https://www.tdameritrade.com/disclosure.html