---
title: "Cantos Closes $70M Fund IV for Deep Tech and Defense"
description: "Cantos closed an oversubscribed $70M Fund IV to lead pre-seed and seed rounds across aerospace, defense, nuclear, biotech, and compute."
date: 2026-07-06T00:00:00.000Z
tags: ["cantos", "fund-close", "deep-tech", "venture-capital", "seed-investing"]
source: https://venturecapitaltracker.com/2026-cantos-70m-fund-iv-deep-tech
---

# Cantos Closes $70M Fund IV for Deep Tech and Defense

> Cantos closed an oversubscribed $70M Fund IV to lead pre-seed and seed rounds across aerospace, defense, nuclear, biotech, and compute.

**Cantos** closed an oversubscribed **$70M Fund IV**, founder and GP Ian Rountree confirmed, to keep leading early deep-tech rounds across aerospace, defense, nuclear, biotech, advanced manufacturing, and compute.

## Key facts

- **Firm:** Cantos (founded 2016, San Francisco)
- **Fund IV:** $70M (oversubscribed; Fund III was $50M)
- **Strategy:** Lead pre-seed/seed with $1.5-4M checks; ~22 companies
- **Notable bets:** Neros (led pre-seed), Castelion, Astranis, Venus Aerospace

## Why this matters

Cantos deliberately kept Fund IV small to maintain high ownership and alignment. The firm has invested in hard tech "since before it was cool," with a defense-and-frontier portfolio now drawing broad interest.

## Sources

1. Cantos $70M Fund IV (Tectonic Defense): https://www.tectonicdefense.com/first-look-cantos-raises-70m-fund-iv/
2. Cantos Fund IV close (Cryptorank, July 6, 2026): https://cryptorank.io/news/feed/cantos-raises-70-m-fund-iv