Castle Securities acquires Morgan Stanley's electronic market making business for US stock options.

According to sources familiar with the matter, Citadel Securities has acquired Morgan Stanley's business focusing on electronic market-making of US stock options. This further solidifies Citadel Securities' dominant position in this popular derivative product field. Sources say that the trading company founded by billionaire Ken Griffin has acquired Morgan Stanley's on-exchange options business and taken over a large number of stock options positions. The deal includes dedicated seats on exchanges such as the Chicago Board Options Exchange, Nasdaq, New York Stock Exchange, and MIAX. Due to the involvement of non-public information, sources have requested anonymity.