Cantos
San Francisco–based early-stage firm founded in 2021, investing at the intersection of software, hardware, and wetware. Cantos closed Fund IV at $70M in 2026, backing defense, climate, and deep-tech founders at pre-seed and seed.
Typical check size
$250K-$3M (stage-based estimate)
Founded
2021
Headquarters
San Francisco, CA
AUM
N/A
Rounds they lead
Pre-Seed
Seed
Rounds they invest
Pre-Seed
Seed
Series A
Portfolio companies we track
Startups in our directory that list Cantos as an investor (4 total).
- Castelion Hypersonic weapons and defense manufacturing startup in the American Dynamism set.
- Heaviside Industries Defense manufacturing and energetics for munitions and hard-tech supply chains.
- Radiant Portable micro-nuclear reactors for remote power and defense applications.
- Radiant Nuclear Portable microreactor company building Kaleidos for remote and defense energy.
Related investment articles
FAQs about Cantos
Stage fit, check size, thesis, and how founders typically approach this firm — based on public sources and our directory.
Cantos leads pre-seed and seed rounds and follows into Series A. Fund IV (2026, $70M) continues the firm's early-stage deep-tech focus. Our directory lists pre-seed and seed as lead stages.
Cantos does not publish a fixed per-deal check. Fund IV closed at $70M (July 2026), implying seed-sized initial checks with follow-on capacity for portfolio companies in defense, climate, and frontier hardware.
Based in San Francisco, CA. Cantos invests in U.S. deep-tech founders — often with hardware, defense, or climate components — regardless of whether teams are Bay Area–based.
The 'near frontier' where software, hardware, and wetware intersect: defense tech, climate/industrial, aerospace, and biotech tools. Our directory tags hardware-semiconductors. Cantos explicitly pursues technically ambitious, capital-intensive bets.
Cantos typically leads or co-leads pre-seed and seed rounds as an early believer in deep-tech companies. It is designed for founders who need patient, technically literate capital at inception.
In our directory: Heaviside Industries (/startup/heaviside-industries), Radiant (/startup/radiant), Radiant Nuclear (/startup/radiant-nuclear), and Castelion (/startup/castelion).
Engage via cantos.vc with a clear technical thesis and prototype or lab results. Warm intros from deep-tech founders, national-security or climate operators, or prior Cantos portfolio teams help.
See /2026-cantos-heaviside-industries-28m-series-a and /2026-cantos-70m-fund-iv-deep-tech for recent Cantos fund and portfolio news.