If you have ever wondered how modern financial markets move at lightning speed, you are looking at an ecosystem built largely by one man. The story of Ken Griffin Citadel Empire is not just about staggering wealth or market dominance; it is a masterclass in how technology, quantitative rigor, and relentless operational scaling reshaped Wall Street. Back in 1990, Ken Griffin started trading from a makeshift office with a convertible phone line and a handful of servers. Fast forward to today, and Citadel along with its sister entity Citadel Securities stands as an absolute titan, processing a massive share of all U.S. retail stock trades. Let us dive into how…