AI Startup Thinking Machines Lab Secures 21,500 SF Office Lease at 79 Fifth Avenue in NYC

Artificial intelligence research startup Thinking Machines Lab has secured a 21,500-square-foot office lease at 79 Fifth Avenue in New York City, establishing its first East Coast presence. The company, founded in early 2025 in San Francisco by former OpenAI CTO Mira Murati, will occupy the entire fourth floor of the Kalimian Properties-owned building, located near Union Square. This move follows the firm's rapid growth, achieving a $12 billion valuation by July 2025, and underscores the continued demand for prime office space from expanding tech and AI companies. Asking rents in the 18-story property are reportedly above $100 per square foot. JLL's Justin Haber and Kyle Riker represented Thinking Machines Lab, while Newmark's David Falk, Daniel Levine, and Dylan Weisman acted on behalf of the landlord. The building also houses other notable tenants such as Capgemini America, Hulu, and The New School, reinforcing its appeal as a strategic location for businesses. This transaction highlights the ongoing strength of New York City's commercial real estate market, particularly for well-capitalized technology firms seeking a presence in key urban centers.