What stage does CyLon Ventures invest at?

CyLon Ventures invests at the Pre-Seed, Seed stages.

What sectors does CyLon Ventures focus on?

CyLon Ventures focuses on Cybersecurity, Deep Tech, Defense Tech.

Where is CyLon Ventures located?

CyLon Ventures is headquartered in Witney, GB.

Does CyLon Ventures lead rounds?

CyLon Ventures typically participates in rounds rather than leading them.

CyLon Ventures

Angel networkInactive

Witney · Pre-Seed–Seed · 14 people tracked

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This fund appears to be inactive.

UK Companies House records show CYLON VENTURES LTD (no. 11425266) as dissolved. It is unlikely to be making new investments — this profile is kept for reference and historical accuracy.

✨ Fox Verdict

Investment thesis

CyLon Ventures specializes in early-stage investing in security and resilience technology companies across Europe and beyond. The team combines national security experience with nearly a decade of work alongside enterprise security startup founders, having been the first backers of companies like Immersive Labs and Tessian. Rather than operating as a traditional VC fund, CyLon invests its own capital to stay founder-aligned, writing angel-sized cheques. It supports portfolio companies through its network and sector expertise, helping them reach early customers, connect with other investors, and build strategic relationships in a challenging sector.

Invests inCybersecurity Deep Tech Defense TechAsia-PacificEuropeIsraelLondonMiddle East & North AfricaUnited KingdomUnited States

Source: firm website, verified Aug 3, 2026.

Stage

Pre-Seed–Seed

Witney, GB

Leads rounds

Follows

Instruments

Equity

Founded

2015

Tracked investments

Team · 14 people

from the firm's website

Alex van Someren

Co-founder of CyLon and the UK Government's Chief Scientific Advisor for National Security. Co-founded nCipher in 1996, leading it to a £350m LSE IPO, and later served as Managing Partner of the Early Stage Funds at Amadeus Capital Partners until 2021.

Grace Cassy· Co-founder

Co-founded CyLon in 2015 with Jonathan Luff and Alex van Someren. She spent 10 years in the UK Diplomatic Service on global security policy and advised Prime Minister Tony Blair on Asia and national security (2004-6). She also co-founded Epsilon Advisory Partners.

Jonathan Luff· Co-founder

Co-founded CyLon in 2015 with Grace Cassy and Alex van Someren. A former senior British diplomat, he served in various UK Government roles including advisor to Prime Minister David Cameron, and co-founded Epsilon Advisory Partners.

Adam Fletcher· CISO, The Blackstone Group

CISO at The Blackstone Group since 2014, having previously held senior roles at Accuvant, Nokia, McAfee and Equifax. Serves as an advisor to CyLon.

Anthony Finkelstein· Former Chief Scientific Advisor for National Security, HM Government

Former HM Government Chief Scientific Adviser for National Security (2015-2021) and now President of City, University of London, with a background in software engineering. Serves as an advisor to CyLon.

Christopher Ahlberg· Co-founder and CEO of Recorded Future

CEO of Recorded Future (sold to Insight Partners in 2019 for $780M) and founder of the Spotfire Division of TIBCO. A member of the Royal Swedish Academy of Engineering Sciences, he serves as an advisor to CyLon.

Ciaran Martin· Former-CEO, National Cyber Security Centre

Professor of Practice at Oxford's Blavatnik School of Government and former head of the UK's cyber security work, having established and run the National Cyber Security Centre. Serves as an advisor to CyLon.

Deneen DeFiore· CISO, United Airlines

Vice President and Chief Information Security Officer at United Airlines, previously Global Chief Information & Product Security Officer at GE Aviation. Serves as an advisor to CyLon.

Jim Rutt· CISO, Dana Foundation

Chief Information Officer/CISO at the Dana Foundation, with extensive cloud security experience and multiple industry certifications, who advises early-stage technology companies. Serves as an advisor to CyLon.

Maria Lewis Kussmaul· Co-Founder of AGC Partners

Co-founder of AGC Partners, leading its cyber security investment banking practice, and previously a co-founder and venture partner of Castile Ventures. Serves as an advisor to CyLon.

Matt Comyns· Managing Partner of Caldwell

Managing Partner of Caldwell's Cyber Security Practice, specializing in recruiting CISOs and cyber security executives, previously leading Russell Reynolds' Global Cyber Security Practice. Serves as an advisor to CyLon.

Min-Liang Tan· Co-Founder & CEO of Razer

Co-founder, Chairman and CEO of Razer Inc and Chairman and CEO of THX Ltd, having grown Razer into a public multinational market leader. Serves as an advisor to CyLon.

Sir Anthony Finkelstein· Former Chief Scientific Advisor for National Security, HM Government

Anthony served as HM Government Chief Scientific Adviser for National Security from 2015-2021 and is now President of City, University of London. His expertise spans software development tools and processes, and he is an active entrepreneur and founder of multiple startups.

Yuval Diskin· Ex-Director of Israeli Internal Security Service

Former Director of the Israel Security Agency (2005-2011), overseeing counter-terrorism, counter-intelligence and critical cyber infrastructure protection. Now works in the cyber security tech sector and advises CyLon.

What they invest in

from 6 of 25 portfolio companies

Cybersecurity ×6Enterprise Software ×5SaaS ×3AI & Machine Learning ×2Data & Infrastructure ×2Cloud Computing ×1Developer Tools ×1

HQs:United States×3United Kingdom×2

Investments · 25 tracked

founders shown can be your intro path

16 Hazyhazy.com

Beauceron

Beauceron Securitybeauceronsecurity.comin 𝕏

Cado Securitycadosecurity.comin 𝕏

Cado Security provides cloud-native forensics and incident response automation that captures disk-level evidence across multi-cloud environments.

Cloud ComputingCybersecurityDeveloper ToolsEnterprise Software

CyberSmart

Digdig.security

Fenix24fenix24.com

Chattanooga, US

Michael Webb(Executive Officer)John Anthony Smith(Executive Officer, Director, Promoter)Zach Powell(Director)Mark Grazman(Executive Officer, Director, Promoter)

Gisualgisual.comin

Go to websiteriskledger.comin 𝕏

Risk Ledger builds a third-party risk management platform that connects organizations to monitor and manage cybersecurity risks in their supply chains.

CybersecurityEnterprise SoftwareSaaSLondon, GB

Haydn BrooksDaniel Saul

Hadrianhadrian.io

Hazy

Immersive Labsimmersivelabs.comin 𝕏

Immersive Labs provides cybersecurity training and labs where teams practice response to emerging threats and current attacker methods.

AI & Machine LearningCybersecurityEnterprise Software<UNKNOWN>, GB

James Hadley(Founder)in

BoardJack Huffard(Chairman of the Board)

Mondoomondoo.ioin 𝕏

Risk Ledger

Seedataseedata.io

SenseOnsenseon.ioin 𝕏

Silent Pushsilentpush.comin 𝕏

Silent Push operates a proprietary scanning and aggregation engine that logs changes across the entire IPv4 and IPv6 space, providing security teams with pre-evaluated first-party data and query functionality to track and monitor attacker infrastructure.

CybersecurityData & InfrastructureSaaSReston, US

Tim Dawson(Director)Kenneth Bagnall(Executive Officer, Director)

BoardDavid Palmer(Director)Frank Verdecanna(Director)John Jensen(Director)

Soverensoveren.ioin

Soveren provides data discovery, monitoring, and intelligence tools that help companies manage sensitive data in compliance with regulations and business rules.

CybersecurityData & InfrastructureEnterprise SoftwareSaaS

Teleskopeteleskope.aiin

New York, US

Brian Schechter(Director)Elizabeth Nammour(Executive Officer, Director, Promoter)Julie Trias(Director)

Tessiantessian.comin 𝕏

Tessian provides AI-powered email security solutions that detect and prevent email-based cyberattacks and data loss for enterprises.

AI & Machine LearningCybersecurityEnterprise Software

Tim Sadler(Founder & CEO)

Vena Security

Venasecurityvenasecurity.comin

Worldrworldr.com

Xapienxapien.comin 𝕏

Zamnazamna.com

Principals & officers · per Companies House

what is this? ⓘ

Neil Christopher Redvers Crocker

Director · British · since 2018

Ownership & control

Neil Christopher Redvers Crocker — right to appoint and remove directors

Frequently asked questions

What stage does CyLon Ventures invest at?: CyLon Ventures invests at the Pre-Seed, Seed stages.
What sectors does CyLon Ventures focus on?: CyLon Ventures focuses on Cybersecurity, Deep Tech, Defense Tech.
Where is CyLon Ventures located?: CyLon Ventures is headquartered in Witney, GB.
Does CyLon Ventures lead rounds?: CyLon Ventures typically participates in rounds rather than leading them.

Images

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