Billionaire Ken Griffin is adding another two floors to Citadel’s future office in Miami’s Brickell Financial District as another wave of employee relocations is expected to hit South Florida over the summer.

Citadel and Citadel Securities said they are adding two floors to their already planned six-floor space at 830 Brickell, in the heart of the city's financial district. The new 55-story tower, developed by OKO Group and Cain International, is the first top-tier office building built in Miami in about a decade.

Despite years of delays after topping off in 2022, 830 Brickell has managed to secure the interest of a wide variety of tenants, including firms like Citadel, Microsoft and private equity firm Thoma Bravo in addition to companies like law firm Baker Mackenzie and Banco Santander.

Citadel’s new space in the building totals eight floors, boosting its original plans for a six-floor office. The move was made after Chicago law firm Winston & Strawn gave up offices at the tower while fellow Chicago law firm Kirkland & Ellis vacated two lower floors for space higher up in the tower, according to Bloomberg.

A representative for Citadel confirmed the expansion but declined to comment further.

Tenants are expected to move into their space at 830 Brickell later this summer. Until then, Citadel has been taking space at the Southeast Financial Center, located at 200 S. Biscayne Blvd., about a mile north in the central business district. The firm expects to have 450 employees in Miami by the end of the summer as new hires and current employees move down to South Florida.

When it opens, 830 Brickell will total 640,000 square feet. The tower, designed by Chicago's Adrian Smith + Gordon Gill, will include a rooftop bar and lounge, restaurant, a wellness center that includes yoga and fitness facilities, a sky lobby with lounge space and work area, an outdoor terrace and a 24-hour concierge service.

The tower commands rents upward of $100 per square foot. More typical space in Brickell usually goes for about $80 per square foot, according to CoStar data.

The new Miami office is just the start of Citadel’s plans in Miami. Griffin, who relocated the firm from Chicago to Miami in 2022, citing Chicago’s violent crime and Florida’s pro-business environment, is reportedly planning a $1 billion headquarters tower in the city and has been quietly acquiring land in the city’s financial district, including one of the financial district’s last remaining waterfront parcels for the future tower.

In the meantime, he has donated millions of dollars to schools, hospitals and projects across Miami. He has regularly appeared in interviews boosting the city, saying that it “represents the future of America” and that perhaps New York could be overtaken by Miami's Wall Street South one day.

Cushman & Wakefield handle leasing on behalf of developers OKO Group and Cain International for 830 Brickell.