SAN FRANCISCO-BASED Cantos Ventures closed its $70 million Fund IV earlier this year, targeting founders building technology in energy, defense, infrastructure, space, and advanced manufacturing.
Founder GP Ian Rountree said the firm kept the fund deliberately small to ensure each company represents a meaningful percentage of the firm's capital. The approach avoids incentive misalignment common in larger funds that treat early checks as options on later rounds.
Cantos has already made ten investments and plans to cap the portfolio at approximately 22 companies. The fund will lead pre-seed or seed rounds with checks ranging from $1.5 million to $4 million.
Rountree emphasized that early-stage investing centers on founders, not unproven business models. "If I've learned anything in this job in 10 years, it's that it's somewhat foolish to think you are underwriting a business that doesn't exist yet," he said. "You're really underwriting the people with the idea—their talent gravity, their intensity, their ability to bend the space-time continuum toward their will."
Cantos was founded in 2016 after Rountree's mentors advised against deep tech investing. He started with Fund I at $4.5 million and committed fully to the sector in 2018 despite initial skepticism.
The firm defines its focus as "near frontier" deep tech and specifically avoids software-only bets. In defense tech, Cantos targets "neo-primes"—companies concentrated on a single product. Portfolio examples include Neros, which builds FPV drones, and Castelion, known for high-speed, lower-cost missiles.
