Alex Stamos
Angel Investor
San Francisco, United States
Alex Stamos is a Series A investor in San Francisco focused on Security and Software. Alex Stamos is the Chief Security Officer at Corridor and previously served at Facebook, Yahoo, and SentinelOne.
- Total investments:
- 4
- Last investment:
- Lead investor:
- 0%
Last updated:
For AI agents: llms.txt
Industries Alex Stamos invests in
Stages Alex Stamos invests in
Countries Alex Stamos invests in
Round sizes
Contacts
| Type | Contact | Validation |
|---|---|---|
| Work email | ||
| Personal email | ||
| Work phone | ||
| Personal phone | ||
| Socials |
Round size
- Series A
- $9M–$16M
Investment Focus
Industry
- Security 3 (75%)
- Software 3 (75%)
- Cyber Security 3 (75%)
- Information Technology 3 (75%)
- Internet 2 (50%)
Stage
- Series A 3 (75%)
- Seed 1 (25%)
Country
- United States 3 (75%)
- Ireland 1 (25%)
Investments
| Company | Description | Round | Links |
|---|---|---|---|
| Encryption infrastructure for developers. | $16.2M / Series A / May 21, 2020 | ||
| Cyberhaven is the data security company revolutionizing how companies protect their important information from theft and misuse.Security products only recognized and protected a limited range of data types because they relied on finding patterns in the content itself. Data tracing technology analyzes billions of events surrounding every piece ofdata to better understand and classify it, allowing for the protection of a broader range of sensitive data in any form, anywhere it goes. | $13M / Series A / Dec 05, 2019 | ||
| Altitude Networks protects cloud collaboration software (SharePoint, OneDrive, Google Drive) from unauthorized data access, sharing to unintended individuals, and data theft. With their DLP application, the client can quickly identify, remediate, and prevent data loss in the cloud with one click. Altitude Networks is deployed at companies as smallas 50 employees and as big as thousands of employees. The solution focuses on simplicity, ease of use, and remediation by leveraging automatic file sensitivity classification, identity mapping to uncover backdoor cloud access via personal accounts of employees, and one click remediation to protect files. | $9M / Series A / Jul 31, 2019 | ||
| Signal Sciences is the fastest growing web application security company in the world. With its award-winning next-gen WAF and RASP solution, Signal Sciences protects more than 40,000 applications and over a trillion production requests per month. Signal Sciences’ patented architecture provides organizations working in a modern developmentenvironment with comprehensive and scalable threat protection and security visibility. The company works with some of the world’s most recognizable companies, like Under Armour, Aflac and WeWork, across industries, including financial services, retail, healthcare, media and entertainment, and government, among others. Signal Sciences is the only vendor to win the Gartner Peer Insights Customers' Choice Award for WAF two times in a row. In addition to customer recognition, Signal Sciences was also named a Visionary in the 2019 Gartner Magic Quadrant for Web Application Firewalls report. The company also won Technology of the Year from InfoWorld and Computing's DevOps Excellence Award for Best DevOps Security Tool. For more information, visit Signal Sciences or follow @SignalSciences. | $2M / Seed / May 20, 2014 |
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FAQ
What does Alex Stamos invest in?
Alex Stamos invests primarily in Security, Software and Cyber Security startups, most often at Series A and Seed stage. Most of the 4 investments tracked by Shizune back companies in United States. The Investment Focus section breaks down every industry, stage and country in the portfolio.
What round sizes does Alex Stamos invest in?
Alex Stamos typically joins rounds of $9M–$16M at Series A. These are whole funding-round sizes, not Alex Stamos's own check, which is rarely disclosed: the 10th–90th percentile of the confirmed public funding rounds Alex Stamos took part in.
How do I contact Alex Stamos?
Public channels for Alex Stamos include LinkedIn, X (Twitter) and the website linked on this profile. For a verified work email and phone number, create a free Shizune account — contact data is searched across 20+ sources and validated before delivery, so your outreach lands in the right inbox.
When did Alex Stamos last invest?
The most recent investment recorded for Alex Stamos closed in May 2020. Shizune tracks 4 investments in total for this profile, including round sizes, stages and portfolio companies, all sourced from confirmed public funding rounds and refreshed monthly.
Is Shizune's investor data accurate?
Yes — every stat on this profile is calculated from confirmed public funding rounds monitored across hundreds of sources since 2020. This profile was last refreshed in Nov 2026 and is updated monthly. Spotted something off? Use the “Suggest an edit” link near the top of the page.
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