Billionaires Behind Kentucky Derby Track Revamp Family Office

The Chicago-based dynasty known for its ties to the Churchill Downs racetrack and a recent $5 billion deal with Blackstone Inc. has revamped its family office’s leadership.

Craig Duchossois, 79, stepped down in recent weeks as executive chairman of the billionaire family’s namesake investment firm, with his daughter Ashley Joyce assuming the chairman role, according to the company’s website. Former Chief Operating Officer Rich Naski was named Duchossois Capital Management’s chief executive officer, replacing Michael Flannery, who spent almost a decade in the position.

A representative for the Duchossois family didn’t respond to requests for comment. The ...