An angel investor, John Brennan has 6 known investments: Valence Security, Opus Security, build.security, Eureka Security, Vulcan Cyber and CAKE Corporation.
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Investment focus
- Focus
- AppSecApplication SecurityCloud SecurityCybersecurityCybersecurity-focusedDevSecOpsEnterprise SecurityVulnerability Management
Contacts
John Brennan portfolio companies (6)
- Valence Security
- Opus Security
- build.security
- Eureka Security
- Vulcan Cyber
- CAKE Corporation
Investor Profile
The known portfolio sits in sectors AI and SaaS, and focus areas AppSec, Application Security, Cloud Security and Cybersecurity.
Stage-wise, the known deals cluster around Seed and Series A rounds.
The portfolio and focus above give founders context on whether John Brennan matches their raise.
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Frequently asked questions
Who is John Brennan?
John Brennan is an angel investor with 6 known investments on file, among them Valence Security, Opus Security and build.security. The sections above list the sectors and stages attached to that record.
What does John Brennan invest in?
Listed sectors include AI and SaaS; listed focus areas include AppSec, Application Security, Cloud Security and Cybersecurity. Those tags come from the companies attached to this profile, so they read as a record of what has been backed rather than a stated preference for what comes next.
What stage does John Brennan invest at?
The known deals of John Brennan include Seed and Series A rounds. Stage is the strongest single filter when you build a target list: an investor with no record at your stage rarely starts with you.
How do I contact John Brennan?
An email address, a phone number and a LinkedIn page are on file for John Brennan. The address stays masked on this page and is readable inside RaiseHunt after you create an account.
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Data: RaiseHunt investor dataset · Snapshot 5 September 2026 · How this data is built · Report a correction or request removal