Mainstay Raises $18M and Acquires Truelist to Expand AI Infrastructure Across Residential Real Estate

By Nazish Shah • Mon Sep 21 2026

Residential real estate technology company Mainstay has raised more than $18 million in growth capital and acquired Truelist, an AI-powered listing platform serving brokers and agents.

The funding round includes new investors Parker89, Stackpoint, Alpaca VC and FJ Labs, alongside existing investors Khosla Ventures, Era Ventures and Clocktower Technology Ventures. Mainstay plans to use the capital to expand beyond large residential investors and bring its data, pricing intelligence and automation infrastructure to brokerages, agents and smaller investors.

Mainstay describes its platform as an intelligent system of record connecting data, decisions and execution across the residential asset lifecycle. Its agentic platform combines customer data, proprietary information and thousands of external sources to support workflows including transaction execution, property taxes, HOA management and payments.

The company says it has facilitated more than $12 billion in real estate transactions, executed 2 million+ agentic workflows across more than 50,000 external portals, and serves 95% of the 60 largest residential real estate investors.

“Residential real estate is still run across an enormous number of disconnected systems, datasets, and manual workflows,” said Dod Fraser, CEO and Co-Founder of Mainstay. “We have spent years building the technology to seamlessly connect data, decisions, and execution for the largest residential investors. This capital and the acquisition of Truelist allow us to bring that same infrastructure to a much broader market of brokerages, agents, and investors.”

The acquisition also brings Carey Armstrong, Founder and CEO of Truelist, into Mainstay as Chief Strategy Officer. Armstrong previously served as Vice President of Premier Agent at Zillow and co-founded and served as COO of Tomo.

“Mainstay and Truelist are both unusual in that their teams have actually built and operated these systems at scale inside the industry’s largest and most innovative residential platforms,” said Clelia Peters, Managing Partner of Era Ventures and a Mainstay board member. “The combination of deep residential real estate experience, a well of proprietary data, and an innovation and AI first approach is unique in the industry, and creates an opportunity to build something foundational.”

Truelist’s listing technology will add a new layer to Mainstay’s platform, helping brokers and agents create, manage and distribute listings while improving data quality and reducing manual work across fragmented MLS systems.

“Mainstay and Truelist have been attacking the same broken system from different angles – Mainstay on behalf of investors, Truelist on behalf of brokers and agents,” said Carey Armstrong, incoming Chief Strategy Officer at Mainstay and Founder/CEO of Truelist. “Joining forces means we stop duplicating effort and start compounding it. I have enormous respect for what Dod and the team have built, and I’m excited about what we can do together.”

The deal marks another step toward a more connected, AI-driven residential real estate ecosystem, bringing data, pricing, listings and workflow automation together across different players in the market.