Its decision to pull out of retail options leaves Morgan Stanley as the sole major Wall Street bank in the business, which is dominated by market makers such as Citadel Securities, Susquehanna, Simplex Trading and Optiver. Citi pulled out because it was unable to compete in a technology arms race to be among the fastest and most reliable venues on Wall Street, people familiar with the talks said.
“Citi does periodic reviews of its business lines,” the company said. “As part of its review of derivatives it was determined to exit the servicing of broker dealers for option executions. The resources are better redeployed to serve clients in other areas of our equities division.”
https://www.ft.com/content/38d23dbf-9fc8-46a0-9597-ce331db8a81f