Citadel Bought Morgan Stanley's Options Market Making Unit in July

In July, Citadel bought Morgan Stanley's equity options market making team, and took on their positions.

Morgan Stanley was the last major bank in the market making business now occupied by HFT firms. 

Jim Esposito, President of Citadel Securities, said "we are maniacally focused on being the best market maker" and also identified what Citadel is not - "we are not a bank".