---
title: "Fab2 Raises $500M Series A at $3.7B to Build the Factory That Builds Chip Fabs"
description: "Fab2, formerly Atomic Semi, raised a reported $500 million Series A at a $3.7 billion valuation to build its own semiconductor equipment, software-defined fabs, and chip-design tools."
date: 2026-09-11T00:00:00.000Z
source: https://venturecapitaltracker.com/2026-fab2-500m-series-a-3-7b
---

# Fab2 Raises $500M Series A at $3.7B to Build the Factory That Builds Chip Fabs

> Fab2, formerly Atomic Semi, raised a reported $500 million Series A at a $3.7 billion valuation to build its own semiconductor equipment, software-defined fabs, and chip-design tools.

**Fab2**, the semiconductor-manufacturing company formerly known as Atomic Semi, raised a reported **$500 million Series A** at a **$3.7 billion valuation**. **Fundomo** led; Fab2's site lists **Corner Capital, Paradigm, Duquesne Family Office, Maverick Silicon, StepStone Group, Protagonist, UDC Ventures, Naval Ravikant**, and others.

this is not only another chip-design bet. Fab2 wants to make the pumps, valves, actuators, chambers, software, tools, and complete factories that manufacture chips. The capital-efficiency claim therefore depends on industrial throughput, not a software launch.

## Key facts

| Field | Detail |
| --- | --- |
| Company | [Fab2](/startup/fab2), formerly Atomic Semi |
| Financing | **$500M Series A** (reported) |
| Valuation | **$3.7B** (reported) |
| Lead | Fundomo |
| Other named investors | Corner Capital, Paradigm, Duquesne Family Office, Maverick Silicon, StepStone, Protagonist, UDC Ventures, Naval Ravikant, others |
| Facilities disclosed | Austin **120,000 sq ft** chip fab; Lockhart **30,000 sq ft** “fab fab”; San Francisco **25,000 sq ft** garage fab |
| Founders | Sam Zeloof and Jim Keller |

## What Fab2 is trying to change

Conventional fabs depend on a concentrated supply chain of specialist equipment vendors. Fab2's answer is vertical integration: make components, assemble them into machines, assemble machines into fabs, and pair the hardware with browser-based collaborative chip-design software.

That creates a large upside case—smaller factories built faster—but also stacks several execution risks into one company. Component yield, process repeatability, equipment uptime, facility utilization, and customer qualification all have to work together.

## Why the investor list matters

Fundomo's lead is joined by a syndicate spanning semiconductor specialists, crossover capital, and early-stage investors. The round gives Fab2 room to build physical capacity before it has disclosed the conventional metrics investors would use to judge a fab: wafer starts, process nodes, yields, utilization, signed customers, or gross margin.

## What remains undisclosed

- Primary versus secondary composition
- Post-money versus pre-money basis for the reported valuation
- Production yield, wafer volume, customer contracts, and revenue
- The process nodes each facility will support
- Capital required beyond this Series A

## Takeaway

At **$500 million**, Fab2 is financed like infrastructure while still described as a Series A startup. The decisive milestone is not another design demo; it is whether the company can make repeatable manufacturing equipment and operate smaller fabs at an economically useful yield.

Day index: [September 11–12 investment news](/2026-september-11-12-investment-news-chips-biotech-fintech).

### Sources

1. [Fab2 — company site and investor list](https://fab2.com/)
2. [Crunchbase News — round amount, stage, and reported valuation](https://news.crunchbase.com/venture/biggest-funding-rounds-boring-co-cognition-massive-week/)

**By:** [Venture Capital Tracker](https://venturecapitaltracker.com/editorial-policy)

**Editorial note:** AI tools assisted with research, structure, or drafting. Venture Capital Tracker retains human editorial responsibility for factual accuracy, relevance, and source quality before publication.