Harvey Raises $550M at $15.5B Valuation as Legal AI ARR Tops $400M

Quick Facts

• Harvey raised $550M at a $15.5B valuation, up from $11B in March 2026, with co-leads from Lightspeed Venture Partners and Diffusion.
• The legal AI company now reports more than $400M in ARR, an 80% increase since January 2026, and serves 3,000-plus customers including 80% of the Am Law 100.
• Harvey also acquired AI agent security startup Guardrails AI, its fourth acquisition of 2026, alongside the funding announcement.

Harvey closed a $550 million funding round on Sept. 9 at a $15.5 billion valuation, the company announced Wednesday. The raise comes roughly six months after Harvey hit an $11 billion valuation and less than a year after a December 2025 round valued the company at $8 billion.

The round was co-led by Lightspeed Venture Partners and Diffusion, a new firm co-founded by Kris Fredrickson, a former Coatue Management investor and longtime Harvey backer. Sequoia, Kleiner Perkins, a16z, Coatue, Goldman Sachs Alternatives, GIC, and Whale Rock were among the other participants. Harvey has now raised more than $1.55 billion total.

Co-founder Winston Weinberg said Harvey has crossed $400 million in annual recurring revenue, up from roughly $190 million in January. That 80-plus percent gain in nine months puts the company’s valuation at approximately 39 times ARR. Harvey now serves more than 3,000 organizations, double the roughly 1,300 it reported earlier this year.

Customers include 80% of the Am Law 100, 20% of the Fortune 500, and half of the Fortune 10. Latham and Watkins and Microsoft’s in-house legal team are among the named clients.

Weinberg told Bloomberg: “All software companies need to turn into AI companies, full stop. Post-training models are going to be part of that process.”

The funding announcement coincided with Harvey’s acquisition of Guardrails AI, a San Francisco-based startup that builds security and reliability infrastructure for AI agents. Guardrails created the first open-source AI guardrails system, which identifies where agents deviate from intended behavior and manages agent risk in real time. Weinberg said Guardrails has spent three years building the answer to the question law firms ask before deploying agents near client work: how do you know what it will do.

The deal is Harvey’s fourth acquisition in 2026. The company previously bought Hexus in January, brought on the Lume AI team in March, and acquired Benchmark, a decision infrastructure platform for asset management, in July. Weinberg said more acquisitions are coming, with a focus on teams rather than products.

The round also follows Harvey’s release of Harvey Tenet, its first in-house post-trained model. Tenet was built on Moonshot’s open-weight Kimi K3 model and trained on legal data with help from inference provider Fireworks. Harvey also launched Harvey LAB, the Legal Agent Benchmark, alongside Tenet. The company is encouraging customers to post-train their own open-weight models as well.

The strategy marks a notable shift. Harvey was partly funded by OpenAI but built its first serious in-house model on a Chinese open-weight system rather than its backer’s technology.

Harvey’s $550 million raise accounts for 16% of the $3.35 billion invested in legal tech companies globally so far in 2026, according to PitchBook data. Combined with Harvey’s previous $200 million raise and competitor Legora’s $600 million Series D, three deals have claimed more than 40% of all legal tech capital raised this year.

Read more: Harvey hits $15.5B valuation, months after reaching $11B