Two software teams chasing the same fragmented market decided the competing part was the expensive part. Seattle’s Truelist, which builds listing tools for brokers and agents, is joining San Francisco’s Mainstay as the buyer raises $18M to widen its AI products across residential property.
Truelist arrived in 2024 with a listing platform built for brokers and agents, who use it to assemble property listings and push them out across a set of MLS systems that remain stubbornly fragmented. On the buyer’s side, Opendoor spun Mainstay out as a standalone business in August 2024; its offering, described by the company as an “intelligent system of record,” handles the data and the transactions that move through a property’s life, with large institutional investors as the core customers.
Carey Armstrong, who founded Truelist and ran it as chief executive, moves over to Mainstay as chief strategy officer. Before Truelist she spent seven years as a Zillow vice president for Premier Agent and co-founded the real estate fintech Tomo, which raised a $40M seed. She described the combination as a chance to stop duplicating effort and start compounding it.
Across the platform’s history, the deals arranged total more than $12B, and 95% of the 60 largest residential real estate investors are clients, according to the company, which Dod Fraser, Opendoor’s former president, now leads. Khosla Ventures, Era Ventures, Parker89, Stackpoint, Alpaca VC and FJ Labs all signed on for the $18M raise. Terms of the acquisition were not disclosed.
