B5 Capital is a Silicon Valley-based single-family office and family seed fund investing in pre-seed, seed, and Series A technology startups. The firm focuses on cash-efficient businesses across AI, cybersecurity, fintech, and climate tech, providing patient family capital to early-stage founders.
Their most common stage is seed (60% of deals). Average disclosed round size is $26.8M (across 4 rounds with reported amounts).
Portfolio
5
Fund Size
—
Top Stage
Seed
Last 12 Mo
0
Team
AB
Alex Bailey
Cofounder
MB
Mark Bailey
Founder and CEO
Portfolio Breakdown
Stage Distribution
Sector Distribution
Investment Activity
DealsAvg Round Size
Portfolio
5 investments
| Company | Round | Amount | Date |
|---|---|---|---|
| TTacta Systems | Series A | $64M | Jun 2025 |
 OpenInfer | Seed | $8M | Feb 2025 |
 Neo Cybernetica | Seed | $30M | Jan 2022 |
 Wardstone | Seed | $5M | — |
 Tacta | Series A | — | — |
Top Co-Investors
Tyche Partners2 shared
EDBI2 shared
America's Frontier Fund2 shared
Sojitz Corporation2 shared
B Capital2 shared
SBVA2 shared
Tau Ventures1 shared
StemAI1 shared
Cota Capital1 shared
Operator Stack1 shared
Future Fund1 shared
Gokul Rajaram1 shared
Essence VC1 shared
SilverCircle1 shared
Toyota Motor Corp.1 shared
Liquid 2 Ventures1 shared
Y Combinator1 shared
Nova Threshold1 shared
New Enterprise Associates1 shared
Cortical Ventures1 shared
Last updated: 19 September 2026