# Clearsky Security
ClearSky Security is the cybersecurity-focused venture capital fund family of ClearSky, a venture capital and growth equity firm with offices in Florida, New York, Boston, and San Francisco that has been operating since 2012.[1](https://www.finsmes.com/2018/08/clearsky-raises-244-7m-for-first-security-venture-capital-fund.html) Its first dedicated security vehicle, ClearSky Security Fund I LLC, a Delaware limited liability company organized in 2016, reported $244.7 million sold toward a $300 million target, and a follow-on vehicle, Clearsky Security Fund I-A LLC, filed a Form D (SEC notice filing for exempt securities offerings) in July 2019 reporting $34.5 million sold; the manager's combined Form D amounts sold total roughly $279.2 million.[2](https://www.sec.gov/Archives/edgar/data/1705289/0001705289-18-000001.txt) • [3](https://www.sec.gov/Archives/edgar/data/1781343/000178134319000002/0001781343-19-000002-index.htm) According to the firm's own Spring 2026 newsletter (self-reported, not independently confirmed), the security fund was still making new investments into 2026.[4](https://www.clear-sky.com/about/spring-2026-newsletter/)
| Fact | Detail |
|---|---|
| Manager | ClearSky, venture capital and growth equity firm, operating since 2012[1](https://www.finsmes.com/2018/08/clearsky-raises-244-7m-for-first-security-venture-capital-fund.html) |
| Address | 700 Universe Boulevard, Juno Beach, Florida (the security fund's address per its Form D); the firm has offices in Florida, New York, Boston, and San Francisco[2](https://www.sec.gov/Archives/edgar/data/1705289/0001705289-18-000001.txt) • [1](https://www.finsmes.com/2018/08/clearsky-raises-244-7m-for-first-security-venture-capital-fund.html) |
| Co-founders | Per the firm's own site (self-reported): Alex (Alexander) Weiss, CEO, Co-Founder & Managing Partner; James Huff, Co-Founder & Managing Partner[5](https://www.clear-sky.com/team/) |
| Focus | Cybersecurity, industrial security, and critical infrastructure security[1](https://www.finsmes.com/2018/08/clearsky-raises-244-7m-for-first-security-venture-capital-fund.html) |
| Funds | Security Fund I: $244.7M sold of $300M target (94 investors); Fund I-A: $34.5M sold (Form D filed 2019-07-03)[2](https://www.sec.gov/Archives/edgar/data/1705289/0001705289-18-000001.txt) • [3](https://www.sec.gov/Archives/edgar/data/1781343/000178134319000002/0001781343-19-000002-index.htm) |
| Combined Form D amounts sold | Approximately $279.2 million across the two security fund filings[3](https://www.sec.gov/Archives/edgar/data/1781343/000178134319000002/0001781343-19-000002-index.htm) |
| Status as of September 2026 | Self-reported as actively investing per the firm's Spring 2026 newsletter[4](https://www.clear-sky.com/about/spring-2026-newsletter/) |
## History and people
The ClearSky platform has operated since 2012, with offices in Florida, New York, Boston, and San Francisco.[1](https://www.finsmes.com/2018/08/clearsky-raises-244-7m-for-first-security-venture-capital-fund.html) The security fund vehicle itself was organized in 2016 as a Delaware limited liability company.[2](https://www.sec.gov/Archives/edgar/data/1705289/0001705289-18-000001.txt)
The 2017–2018 Form D filings for Security Fund I list five related persons, all at the [Juno Beach](https://www.edgepedia.org/juno-beach) address: Alexander Weiss, Jay Leek, James Huff, James Goldinger, and Peter Kuper, with Alexander Weiss signing as Managing Director.[2](https://www.sec.gov/Archives/edgar/data/1705289/0001705289-18-000001.txt) The firm's own site identifies Weiss as CEO, Co-Founder & Managing Partner and Huff as Co-Founder & Managing Partner; these titles are self-reported and not independently confirmed.[5](https://www.clear-sky.com/team/) Chatsworth Securities LLC of Greenwich, Connecticut (CRD 40804) is listed on the filing as the placement agent for the offering.[2](https://www.sec.gov/Archives/edgar/data/1705289/0001705289-18-000001.txt)
Personnel have changed since the fund filings. According to the firm's Spring 2026 newsletter (self-reported), Ryan Crum joined ClearSky as Partner, bringing what the firm describes as more than two decades of cybersecurity and technology leadership from [Apollo Global Management](https://www.edgepedia.org/apollo-global-management), where he served as Chief Security Officer and Chief Technology Officer.[4](https://www.clear-sky.com/about/spring-2026-newsletter/) The public record retrieved here does not establish whether Leek, Goldinger, or Kuper remain with the firm.
## Strategy
ClearSky invests through two vehicles on one platform: ClearSky Power & Technology, focused on enterprise technology with a power-sector angle, and ClearSky Security, which invests in companies offering solutions for cybersecurity, industrial security, and critical infrastructure security.[1](https://www.finsmes.com/2018/08/clearsky-raises-244-7m-for-first-security-venture-capital-fund.html) The security funds and the energy/technology funds therefore share the same managers and investment organization rather than operating as separate firms.[1](https://www.finsmes.com/2018/08/clearsky-raises-244-7m-for-first-security-venture-capital-fund.html) The firm's Spring 2026 newsletter (self-reported) records continued parallel activity by the sibling funds, with ClearSky Fund IV co-leading XGS Energy's Series B in February 2026 and ClearSky Power II investing $2 million in Renew Home's $50 million round in April 2026.[4](https://www.clear-sky.com/about/spring-2026-newsletter/)
The sources retrieved do not specify the firm's stage range or typical check size, nor how its security-sector specialization changes deal structure or value-add relative to generalist venture funds beyond the sector focus itself.
## Funds by the numbers
**ClearSky Security Fund I LLC.** The fund's Form D amendment filed in August 2018 reported a $300,000,000 offering, of which $244,700,000 had been sold and $55,300,000 remained unsold, with 94 investors.[2](https://www.sec.gov/Archives/edgar/data/1705289/0001705289-18-000001.txt) The date of first sale was recorded as 2017-08-04, and the original Form D was signed on 2017-08-09.[2](https://www.sec.gov/Archives/edgar/data/1705289/0001705289-18-000001.txt) Trade press reporting at the time corroborated the $244.7 million raised from 94 investors against the $300 million final target.[1](https://www.finsmes.com/2018/08/clearsky-raises-244-7m-for-first-security-venture-capital-fund.html) • [6](https://regtechanalyst.com/clearsky-raises-244-7m-for-first-security-fund/)
**Clearsky Security Fund I-A LLC.** A separate Delaware entity located in Florida (CIK 0001781343), it filed a Form D notice of exempt offering on 2019-07-03 under file number 021-343508, reporting $34,532,500 sold.[3](https://www.sec.gov/Archives/edgar/data/1781343/000178134319000002/0001781343-19-000002-index.htm)
Combined, the manager's two security fund filings account for approximately $279.2 million in Form D amounts sold.[3](https://www.sec.gov/Archives/edgar/data/1781343/000178134319000002/0001781343-19-000002-index.htm)
## Portfolio and exits
Early portfolio companies named in 2018 trade press include BigID, where ClearSky joined Comcast Ventures and others in a $30 million Series B; Preempt, in a $17.5 million Series B; IntSights, an intelligence-driven security provider; and Inky, an email protection gateway using AI, machine learning, and computer vision to block phishing.[6](https://regtechanalyst.com/clearsky-raises-244-7m-for-first-security-fund/)
Three exits are reported in the firm's Spring 2026 newsletter; these are self-reported claims by the firm, not independently confirmed here:
- In January 2026, Security I portfolio company Altamira, described by the firm as a prime contractor for U.S. government cybersecurity and space services, was acquired by Parsons for $330 million in cash at closing plus a $45 million cash earn-out payable in Q1 2027 subject to 2026 EBITDA targets.[4](https://www.clear-sky.com/about/spring-2026-newsletter/)
- In October 2025, Security I portfolio company Inky, an AI-based anti-phishing platform, was acquired by Kaseya.[4](https://www.clear-sky.com/about/spring-2026-newsletter/)
- In September 2025, Harness acquired Fund IV portfolio company Qwiet AI, an AI-powered vulnerability detection company.[4](https://www.clear-sky.com/about/spring-2026-newsletter/)
## Recent developments
The firm's Spring 2026 newsletter (self-reported) indicates the security fund remained active well after its 2019 filing: in December 2025, Security I invested $1 million in Mitiga's $6.6 million Series B extension round, and in March 2026 it backed Query.AI's convertible note round.[4](https://www.clear-sky.com/about/spring-2026-newsletter/) The same newsletter records the three exits above and the addition of Ryan Crum as Partner.[4](https://www.clear-sky.com/about/spring-2026-newsletter/)
## References
1. [ClearSky Raises $244.7M for First Security Venture Capital Fund — FinSMEs (August 2018)](https://www.finsmes.com/2018/08/clearsky-raises-244-7m-for-first-security-venture-capital-fund.html)
2. [SEC Form D/A — ClearSky Security Fund I LLC (amendment filed 2018-08-07)](https://www.sec.gov/Archives/edgar/data/1705289/0001705289-18-000001.txt)
3. [SEC Form D — Clearsky Security Fund I-A LLC (filed 2019-07-03)](https://www.sec.gov/Archives/edgar/data/1781343/000178134319000002/0001781343-19-000002-index.htm)
4. [ClearSky — Spring 2026 Updates (firm's own newsletter)](https://www.clear-sky.com/about/spring-2026-newsletter/)
5. [ClearSky — Meet Our Team (firm's own site)](https://www.clear-sky.com/team/)
6. [ClearSky raises $244.7m for first security fund — The RegTech Analyst](https://regtechanalyst.com/clearsky-raises-244-7m-for-first-security-fund/)
---
*Topic: Encyclopedia › Society and history › Economics and business › Finance › Venture capital and private equity › Venture capital firms of the Americas › Enterprise software and cloud investors › Titles symbols to I*
*Initially written Sep 17, 2026 · Edited: Oct 11, 2026; Oct 15, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license