Mirendil seeks $1B round at $5B valuation, three months after seed

Mirendil Inc., a San Francisco AI lab founded by former Anthropic, xAI, and OpenAI staffers, is in talks to raise up to $1 billion in a new funding round that would value the company at $5 billion, according to Bloomberg^1,3. Kleiner Perkins is in discussions to lead the round, and Andreessen Horowitz, which co-led Mirendil's seed alongside Kleiner Perkins, is negotiating to invest again². Neither firm has commented publicly.

The valuation would represent a fivefold increase from where Mirendil stood in June, when the company raised its seed round. The company has no public product.

Founders and thesis

Mirendil was founded in December 2025 by four people with backgrounds at Anthropic, xAI, and OpenAI. Co-founders Behnam Neyshabur and Harsh Mehta met at Google in 2019. Neyshabur went on to co-lead Google DeepMind's Blueshift team, while Mehta built the first version of Anthropic's internal AI-research platform. Both joined Anthropic in late 2024 and left together in December 2025.

When Neyshabur announced the seed round in June, he framed the company's mission in a single line: "the most important application of AI is AI itself". Mirendil's bet is that automating AI research is a capability the largest labs use internally but do not sell externally. Anthropic has said Claude now writes the majority of the code merged into its own codebase. Mirendil aims to be the company that commercializes that kind of self-improving research loop for outside customers.

Neolab funding wave

Mirendil is part of a broader cohort that the source describes as "neolabs," startups that have collectively pulled in tens of billions of dollars in the past year on the premise that automating AI research itself is the highest-leverage investment in the industry.

ANALYSIS A $5 billion valuation for a three-month-old company with no shipping product places the entire bet on the founding team's pedigree and the perceived size of the self-improving-AI market. The round's structure, with both Kleiner Perkins and Andreessen Horowitz returning from the seed, concentrates governance among a small set of backers.

Anthropic, Mirendil's talent source, released Claude Opus 5.5 on September 22 with substantial API price cuts^[1]. ◆ Mirendil's fundraise lands the same week its former employer is competing aggressively on model pricing, underscoring how quickly capital is flowing both to incumbents and to the researchers who leave them.