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Osney Capital

www.osneycapital.com · Witney, Oxfordshire, UK

“The UK's cyber ecosystem is one of the country's greatest untapped strengths. Osney Capital provides specialist capital to back the next wave of UK cyber founders and build globally significant cybersecurity companies.”

$330K – $3.3M
Check Size
Leads
Lead Tendency
$64M
AUM
01Investment Thesis

They combine deep cybersecurity domain expertise, venture experience (125+ seed investments), and fund structuring knowledge.

Exclusion Criteria

No non-cybersecurity investments. No late-stage deals. No companies outside UK/Canada geographic focus.

02Investment Team
JW
Joshua Walter
Founding Partner
AC
Adam Cragg
Partner
PW
Paul Wilkes
Partner
03F4 Research Brief

Osney Capital Research

Investment Thesis

Osney Capital is the UK's first specialist cybersecurity seed fund, focused exclusively on backing early-stage UK cyber companies. Founded in 2024 by Joshua Walter, Adam Cragg, and Paul Wilkes — all Oxford MBA alumni — the firm believes the UK's cyber ecosystem is one of the country's greatest untapped strengths and that specialist capital is needed to build globally significant cybersecurity companies. The firm provides not just capital but deep sector expertise, leveraging the team's combined decades of experience across cybersecurity operations (NCC Group), venture capital (Quake Capital, 125+ seed investments), and financial services law (Collas Crill).

Osney is accredited by the UK's National Security Strategic Investment Fund (NSSIF), indicating government security vetting and demonstrated technical capabilities in the cybersecurity domain. The firm also partners with Cyber Runway by Plexal, HMGCC CoCreation, UKC3, and Cyber ASAP.

Sector Focus

Osney Capital invests exclusively in cybersecurity, with particular emphasis on:

  • AI security and safety (AI model testing, agentic AI supervision)
  • Identity and access management
  • Counter-disinformation and information warfare
  • Hardware-enforced network security and quantum-resistant encryption
  • Vulnerability management and pen testing platforms
  • CISO security tool optimization
  • Fraud intelligence and financial crime prevention
  • Software supply chain security and binary analysis
  • Breach detection and deception technology
  • Security operations and threat hunting

The firm covers the full breadth of cybersecurity subsectors, from defensive to offensive security, and has shown strong interest in AI-adjacent cybersecurity applications.

Stage Focus

Osney focuses on pre-seed and seed stage investments, specifically targeting first institutional rounds where total round size is less than £5M. They plan to build a portfolio of approximately 30 companies. They also maintain capacity for follow-on investments in Series A rounds for existing portfolio companies.

Check Size

Typical investment: £250,000 to £2,500,000 (~$330K to $3.3M)

  • Pre-seed: £250K-£500K
  • Seed: £500K-£2.5M
  • Series A follow-on capacity maintained

Osney has led several rounds including Ploy (£2.5M seed) and Overmind (£2M pre-seed), demonstrating willingness to write checks at the top of their range and take lead positions.

Fund Details

Fund I closed above its £50M (~$64M) target, oversubscribed despite challenging conditions for first-time managers. The fund is backed by a notable LP base:

  • British Business Bank — cornerstone investor, committed up to £36M
  • IronGate Capital Advisors — US-based defense-focused fund of funds
  • East X Ventures — London-based investment group
  • Exited UK cyber entrepreneurs and senior national security figures
  • Canadian family offices (undisclosed)

Recent Activity

Osney has been actively deploying from Fund I since mid-2024:

  • February 2026: Participated in Refute's £5M seed round (counter-disinformation AI, co-led by Amadeus Capital Partners)
  • January 2026: Invested in Aisy's $2.3M seed round (AI-powered vulnerability prioritization)
  • September 2025: Led Overmind's £2M pre-seed (agentic AI security layer, founded by former MI5 engineer)
  • October 2025: Led Ploy's £2.5M seed round (identity and access management, Josh Walter joined board)
  • June 2024: Invested in OnSecurity's £5.5M seed round (pen testing platform, co-invested with Gresham House)
  • February 2024: Invested in ESProfiler's £2.8M seed round (CISO security optimization)

Pre-fund angel investments validated their thesis: Sitehop (Sheffield), OnSecurity (Bristol), ESProfiler (Manchester), Mindgard (Lancaster), RevEng.AI (London), and Seedata (London).

Portfolio Highlights

Osney's 12-company portfolio spans the cybersecurity landscape:

AI Security: Mindgard (continuous automated red teaming for AI systems, Lancaster University spin-out), Overmind (supervision layer for agentic AI, ex-MI5 founder)

Identity & Access: Ploy (AI-powered identity governance for mid-market, founded by ex-Metomic leaders)

Counter-Disinformation: Refute (AI-powered disinformation detection, detected 32,500 suspicious TikTok videos in Romanian election)

Hardware Security: Sitehop (quantum-resistant hardware encryption, raised £13.5M total including £7.5M Series A from Northern Gritstone)

Vulnerability Management: Aisy (AI-native vuln prioritization, founded by former HackerOne Head of Hacker R&D), OnSecurity (automated pen testing, Bristol-based, 35+ employees)

Supply Chain Security: RevEng.AI (binary analysis via AI, raised $4.15M from Sands Capital and In-Q-Tel)

Fraud Intelligence: Aviel Technologies (AI-generated personas infiltrate criminal networks, London-based)

CISO Tools: ESProfiler (security portfolio optimization for CISOs, Manchester-based)

Breach Detection: Seedata (deception technology with decoy data, London-based)

Security Operations: Huntbase (AI-driven SOC platform for alert triage, London-based)

Team

Joshua Walter, Founding Partner — Former director at NCC Group leading the Financial Services Sector business, one of the largest cybersecurity providers. Deep expertise in market strategy, demand analysis, and enterprise cybersecurity. MBA from University of Oxford, First-class honours in Civil Engineering from University of Birmingham.

Adam Cragg, Partner — Former Chief of Staff at MIT Entrepreneurship Center, founding manager of NYU Entrepreneurship Lab, and founding partner of Quake Capital (Forbes top-10 global VC, 2nd most active investor backing female founders). Has invested in 125+ seed-stage startups with audited top-decile track record. MBA from University of Oxford, BA from University of British Columbia. Based partly in Calgary for Canadian expansion.

Paul Wilkes, Partner — Over 15 years in financial services and regulatory law. Former partner at Collas Crill LLP where he led the corporate team, overseeing 50+ employees across five jurisdictions and growing revenues 5x. Expertise in VC fund structuring, M&A, and financial services regulation. MBA from University of Oxford, LLB from University of New South Wales.

Geographic Focus

Primarily United Kingdom, with active expansion into Canada (Calgary office opening). The firm helps UK/European cybersecurity startups enter North American markets and vice versa. All 12 current portfolio companies are UK-based, spread across London, Sheffield, Bristol, Manchester, and Lancaster.

Decision Process

Partnership model with three equal partners. Joshua Walter has taken board seats (e.g., Ploy), indicating active involvement post-investment. The team combines cybersecurity domain expertise (Walter), venture/startup expertise (Cragg), and legal/fund structuring expertise (Wilkes).

Founder Preferences

Osney backs technical cybersecurity founders, often with deep domain backgrounds:

  • Former intelligence agency engineers (MI5/MI6/GCHQ — Overmind)
  • University spin-outs and researchers (Mindgard from Lancaster)
  • Former security practitioners and bug bounty experts (Aisy from HackerOne)
  • Repeat founders with enterprise security experience (Ploy from Metomic)

The firm explicitly targets the UK cyber ecosystem and has strong ties to government security programs through NSSIF accreditation.

04Selected Portfolio
Enterprise Software
Ploy
Healthcare & Digital Health
Aisy·Overmind
Security & Cybersecurity
Refute·Huntbase·Aviel Technologies·Sitehop·Mindgard·OnSecurity·RevEng.AI·ESProfiler·Seedata·Strand Intelligence·Ossprey
Open the full portfolio→
05Recent Updates

Fresh signals from public announcements, essays, and portfolio activity.

Osney Capital invested in Ossprey, a software supply chain security company that reads code inside open source packages to detect malicious intent using static and behavioural analysis with AI. Ossprey is listed on Osney's portfolio page alongside other Fund I investments.
INVESTMENT·osneycapital.com
Added recently
Osney Capital closed its debut fund oversubscribed at the £60m hard cap, making Fund I one of the largest debut seed funds in UK history. New LPs at final close include Imperial College London's Endowment and Planet First Partners. The fund is anchored by the British Business Bank through the ECF programme and NSSIF-accredited.
NEW FUND·osneycapital.com
JUN 29, 2026
Closed its oversubscribed debut cyber seed fund at a £60m hard cap.
NEW FUND·techfundingnews.com+1
JUN 29, 2026
Led Strand Intelligence's £1m seed round for DFIR automation.
INVESTMENT·businesscloud.co.uk
JUN 10, 2026
06Frequent co-investors
AC
Amadeus Capital Partners
Both backed 2 of the same companies
Sitehop, Refute
EO
Episode One Ventures
Both backed 2 of the same companies
RevEng.AI, Refute
IC
IQ Capital
Both backed 2 of the same companies
Mindgard, RevEng.AI
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Quick Reference
Check Size
$330K – $3.3M
Stages
Pre-Seed · Seed
AUM
$64M
Decision
Partnership
Warm Intro
Not Required
Involvement
Board Seat
Location
Witney, Oxfordshire, UK
Sector Focus
Security & Cybersecurity
Models
Cybersecurity ProductsSecurity SaaS
Technology
AI/MLHardware SecurityQuantum Computing
See all Security & Cybersecurity investors →
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F4 Intelligence Report · Last Researched September 25, 2026F4 Research Engine