It seems unlikely to me that Citadel would be liable. They're just processing bulk transactions -- they have no direct contact with customers. You could just as well blame the NYSE.
If it's true they refused to process for certain securities for their downstream clients, then I believe "When?" and "Why?", specifically in relation to other actions, become legally relevant questions.
If it's true they refused to process for certain securities for their downstream clients, then I believe "When?" and "Why?", specifically in relation to other actions, become legally relevant questions.