# Sounil Yu

> Sounil Yu is a seed investor at JupiterOne backing Cyber Security. See 6 investments, check sizes, portfolio and contact details. Updated Aug 2026.

- Type: Angel Investor
- Fund: JupiterOne
- Location: Washington, United States
- Total investments: 6
- Last investment: Feb 2023
- Lead investor: 0%
- Last updated: Aug 2026
- LinkedIn: https://www.linkedin.com/in/sounil/
- X (Twitter): https://twitter.com/sounilyu?lang=en

Sounil Yu is a seed investor at JupiterOne in Washington focused on Cyber Security and Network Security. Sounil Yu is the CISO & Head of Research at JupiterOne. Sounil Yu attended Duke University.

## Contacts

5 contacts available for Sounil Yu: work email, personal email, work phone, personal phone and socials. Sign up free to unlock them: https://app.shizune.co/sign-up/investor-profiles/find-email/sounil-yu?utm_source=investor_profile

## Round sizes

| Stage | Round size |
| --- | --- |
| Seed | $2.8M–$9.8M |

## Investment focus

### Industry

| Industry | Investments | Share |
| --- | --- | --- |
| Cyber Security | 5 | 83% |
| Network Security | 3 | 50% |
| SaaS | 2 | 33% |
| Security | 2 | 33% |
| Software | 2 | 33% |

13 industries tracked in total.

### Stage

| Stage | Investments | Share |
| --- | --- | --- |
| Seed | 5 | 83% |
| Series A | 1 | 17% |

### Country

| Country | Investments | Share |
| --- | --- | --- |
| Israel | 2 | 33% |
| United States | 2 | 33% |
| Canada | 1 | 17% |

## Investments

| Company | Description | Amount | Stage | Date | Website |
| --- | --- | --- | --- | --- | --- |
| Sublime Security | Open, adaptable email security. | $9.8M | Seed | Feb 21, 2023 |  |
| Feroot Security | All-in-One Client-Side Risk Management Platform Feroot is the first way to manage and automate everything you need to protect your data assets on the client-side of your web applications and websites – from credit card data to login credentials, ePHI, and more. All in one, online platform. | $2.8M | Seed | Jul 18, 2021 |  |
| Grip Security | Grip Security brings comprehensive visibility across an enterprise’s entire SaaS portfolio—known or unknown for SaaS applications, users, and their interactions—with extreme accuracy and deployment in minutes. Grip assists businesses in modernizing their security architecture to meet the needs of today's SaaS acquisition and use. The SaaSSecurity Control Plane (SSCP) solution is a fundamentally different approach that enables security teams to embrace a business-led IT strategy in a safe and secure manner. | $6M | Seed | Apr 20, 2021 |  |
| SPHERE | SPHERE is a cybersecurity company that provides software and services to improve data governance, security, and compliance across data, platforms, and applications.It enables businesses to secure their sensitive data and create a governance framework to control access to systems and assets. The company is developing its managed serviceoperations, including its purpose-built automation platform, SPHEREboard, along with targeted SME's across the SPHERExperts team. Together, this solution is described as SPHEREsoftserve, which combines automation and expertise to provide a seamless and effective solution to SPHERE's customers. SPHEREsoftserve provides a unified approach, improving processes and procedures leveraging technology and skillset for a consistent and predictable outcome.In 2009, Rita Gurevich headquartered SPHERE in Hoboken, New Jersey. | $10M | Series A | Feb 18, 2021 |  |
| build.security | Build.Security provides developers with easy deployment, ecosystem integrations, and code extensibility. The company is leveraging Open Policy Agent and the power of open-sourcing, which uses API-based data sources to help build and enforce enterprise-grade access controls across application portfolios.Build.Security was founded in 2020 and isbased in Sunnyvale, California. | $6M | Seed | Nov 18, 2020 |  |
| Enso Security | Enso is an information security startup that offers an application security posture management solution. | $6M | Seed | Oct 28, 2020 |  |

6 of 6 investments shown.

## Co-investors
- [StoneMill Ventures](https://shizune.co/investors/profile/stonemill-ventures) — VC Fund, 3 deals together
- [YL Ventures](https://shizune.co/investors/profile/yl-ventures) — VC Fund, 3 deals together
- [Forgepoint Capital](https://shizune.co/investors/profile/forgepoint-capital) — VC Fund, 2 deals together
- [Preface Ventures](https://shizune.co/investors/profile/preface-ventures) — VC Fund, 2 deals together
- [SAV (Scale Asia Ventures)](https://shizune.co/investors/profile/scale-asia-ventures) — VC Fund, 2 deals together
- [Decibel Partners](https://shizune.co/investors/profile/decibel-vc) — VC Fund, 1 deal together

## About JupiterOne

VC Fund · Morrisville, United States

JupiterOne is a security product designed to help organizations manage their cloud-based infrastructure. It reduces the cost and complexity of cloud security, replacing guesswork with granular data about cyber assets and configurations. Its software helps security operations teams shorten the path to security and compliance and improve theiroverall posture through continuous data aggregation and relationship modeling across all assets. The company was founded as a subsidiary of LifeOmic, a cloud-native healthcare software company.

5 contacts available at JupiterOne.

| Name | Title | Profile |
| --- | --- | --- |
| Sounil Yu | CISO & Head of Research | https://shizune.co/investors/profile/sounil-yu |
| Brian J. Kelly | Chief Revenue Offier | — |
| Erkang Zheng | CEO & Founder | — |
| Jackson Evans | Director of Finance and Strategy | — |
| Mark Miller | Senior Director, Content Marketing | — |

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- [Right Side Capital Management](https://shizune.co/investors/profile/right-side-capital-management) — VC Fund

## FAQ

### What does Sounil Yu invest in?

Sounil Yu invests primarily in Cyber Security, Network Security and SaaS startups, most often at Seed and Series A stage. Most of the 6 investments tracked by Shizune back companies in Israel. The Investment Focus section breaks down every industry, stage and country in the portfolio.

### What is Sounil Yu's check size?

Sounil Yu typically joins rounds of $2.8M–$9.8M at Seed. These ranges are 10th–90th percentile round sizes calculated from confirmed public funding rounds, so they are a realistic guide to the rounds Sounil Yu participates in.

### How do I contact Sounil Yu?

Public channels for Sounil Yu include LinkedIn and X (Twitter). 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 Sounil Yu last invest?

The most recent investment recorded for Sounil Yu closed in Feb 2023. Shizune tracks 6 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 Aug 2026 and is updated monthly. Spotted something off? Use the “Suggest an edit” link near the top of the page.

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