Refactor Capital's Zal Bilimoria closes Fund V at $50M as PathAI is acquired by Roche for $1B

Refactor Capital's Zal Bilimoria closes Fund V at $50M

Zal Bilimoria runs Refactor Capital as its sole employee — no partners, no full-time staff, just an AI calendaring tool called Blockit that replaced a part-time executive assistant three months ago. That setup is a deliberate constraint, not a limitation. Across ten-plus years and five funds, Bilimoria has built $300M in AUM while writing concentrated seed checks of $1–2M into deep tech, bio, energy, aerospace, and critical materials.

The week he announced Fund V closing at $50M, two other things landed simultaneously. Astranis — the first check he wrote after leaving Andreessen Horowitz, a seed round he led — closed a $450M Series E at a $2.8B valuation. And PathAI, another Refactor seed investment, was acquired by Roche for $1B.

“Wednesday, Astranis raises a $450,000,000 Series E. This was the first check I wrote after I left Andreessen Horowitz... And then on Thursday, I launched my new fund. Fund five. I've got $300,000,000 under management. Another $50,000,000. I just raised $50,000,000 fund... Something pops up in my feed: PathAI got acquired by Roche for a billion dollars.”

The fund math

Bilimoria keeps the fund size flat despite having more than $50M of LP interest in Fund V. The logic is straightforward: a concentrated portfolio of 20–25 companies at 10% entry ownership, after dilution, leaves roughly 5%. Five percent of a $1B outcome returns the fund. Scale the fund without scaling the team, and adverse selection creeps in — marginal companies get funded, and ownership per deal shrinks. He cites top-decile seed performance historically requiring at least one fund returner, and structures everything around hitting that bar rather than diversifying his way to mediocrity.

Rising valuations at pre-seed and seed in hard tech are already forcing him to make exceptions on target ownership for the highest-quality deals, accepting lower entry stakes in companies where he believes the outcome could reach $10B or $100B rather than $1B.

Sourcing and diligence in hard tech

Bilimoria relies on a network of professors, advisors, and founders who vet technical claims in exchange for early access — they want to invest or advise, so they engage for free. The diligence framework is founder-first. His example is General Galactic, an LA-based propulsion startup founded by former SpaceX and Varda team members building water-based electrolyzer engines for satellites. He backed founders Halen and Luke at pre-seed with just a deck, citing their references and urgency. The company has since pivoted once and counts the Space Force among early supporters.

His stated failure mode is falling in love with an idea rather than a team — he flags it as a pattern he actively monitors in himself.

Career backdrop

Bilimoria's operating history runs through Google's AdWords and AdSense teams under Susan Wojcicki, YouTube during its cash-burning early monetization years, Netflix as its first head of mobile following the iPad launch, LinkedIn, and then Andreessen Horowitz from 2013, where he helped launch the firm's first sector-specific vehicle — the $200M Bio Fund in 2015 — before spinning out Refactor Capital roughly a decade ago.

At YouTube, his role centered on getting Fortune 500 brands comfortable with UGC-adjacent placements. The mechanism was homepage takeovers sold at $1–2M per day, bundled with mandatory search and display spend on YouTube itself, easing brands into ongoing campaigns rather than one-off buys. He describes building that business to "a few hundred million" in revenue; YouTube reported approximately $20B last year.

Portfolio snapshot

Refactor currently has six unicorns in the portfolio. Beyond Astranis and PathAI, Bilimoria mentions a nuclear energy company among the holdings he expects to reach significant scale. He writes checks across robotics, physical AI, and critical materials alongside aerospace and bio — categories where, in his view, the outcome distribution is shifting toward $10B–$100B rather than clustering at $1B.