Series X Capital

VC firm · San Francisco, CA

Verified active in the last 12 monthsSEC-registered adviser

Venture firm based in San Francisco, CA. Most recent fund on file: Series X Capital Fund I, L.P. ($542M offering), filed Mar 2026.

“An independent venture fund backing moonshots from Alphabet's X, The Moonshot Factory. Over $600 million under management and exclusive rights to X spinouts.” (from the firm’s website)

Stages: Seed
Typical check (est.): $5.42M–$16.3M
Latest fund: $542M · Mar 2026
Last verified activity: Dec 2025

Focus

HealthcareAI & MLFintechDeveloper Tools

Funds and vehicles on SEC file

Series X Capital Fund I, L.P.
Fund · $542M offering
Mar 2026
Series X Capital Affiliates Fund I, L.P.
Fund · $25M offering
Dec 2025

Sources

SEC Form D: Series X Capital Fund I, L.P.Mar 10, 2026
SEC Form D: Series X Capital Affiliates Fund I, L.P.Dec 12, 2025
SEC adviser record: Series x CapitalMar 31, 2026
Firm websiteOct 12, 2026

Profile last verified Oct 12, 2026. Is this you? Correct or remove this profile.