Mainstay acquires Truelist in $18M round; ex-Zillow VP Carey Armstrong named chief strategy officer

Seattle startup Truelist, founded by ex-Zillow VP Carey Armstrong in 2024, was acquired by San Francisco real estate tech firm Mainstay as part of an $18 million growth funding round to expand AI listing and transaction tools across the residential market. Armstrong will join Mainstay as chief strategy officer as the company broadens from serving institutional investors to brokerages, agents and smaller property owners.