“The public U.S. securities industry, which moves trillions of dollars a day, still relies on mainframe technology from the 1980s. These legacy systems are entrenched in manual processes and siloed data, resulting in costly errors and expensive technical debt.”

https://techcrunch.com/2023/04/11/clear-street-raises-270m-at-a-2b-valuation-to-grow-tech-enabled-independent-prime-brokerage-platform/