StoneMill Ventures
Angel networkWashington · Seed–Series A · 1 people tracked
Investment thesis
StoneMill Ventures backs disruptive cybersecurity companies, primarily at the seed stage. The firm positions itself as an active, hands-on investor that seeks founding teams able to benefit from its experience building pioneering security companies. It concentrates its investing in the Washington, DC metro area where it can be closely involved with portfolio companies, but will consider opportunities globally when the fit is right. The firm looks for passionate entrepreneurs aiming to disrupt key parts of the security ecosystem and founders who want mentorship in addition to capital.
Source: firm website, verified Aug 7, 2026.
Team · 1 people
from public directories
What they invest in
from 25 of 36 portfolio companiesCybersecurity ×21SaaS ×15Enterprise Software ×12AI & Machine Learning ×11Cloud Computing ×4Data & Infrastructure ×4Defense Tech ×3Developer Tools ×2
HQs:United States×9Canada×1
Investments · 36 tracked
founders shown can be your intro pathTest range infrastructure for autonomous vehicles (unmanned aerial, ground, and marine systems) serving commercial and defense sectors.
Defense TechHardwareRoboticsDuluth, US
Matt Thomasson(Executive Officer)Steven Witt(Executive Officer, Director)Michael Cutrone(Director)Laura Barr(Director)
BoardCyndi Gula(Director)in
PartnerMichael Sutton· solo GP
Atomic OSSEC is an enterprise security platform offering real-time file integrity monitoring (FIM) and endpoint detection and response (EDR), delivered as SaaS to protect endpoints and cloud workloads.
Cloud ComputingCybersecuritySaaS
PartnerMichael Sutton· solo GP
PartnerMichael Sutton· solo GP
PartnerMichael Sutton· solo GP
PartnerMichael Sutton· solo GP
Cybrary provides online cybersecurity training courses, certification prep programs, and hands-on labs for individuals and enterprise teams.
CybersecurityEdTechSaaSRiverdale, US
Ryan J. Cory(Executive Officer, Director)Ralph, Jr. P. Sita(Executive Officer, Director)Jeremy Gehring(Executive Officer, Director)
BoardKlee Kleber(Executive Officer, Director)Ron Gula(Director)inJim Curry(Director)in
PartnerMichael Sutton· solo GP
Textie is a consumer AI platform that combines multiple AI tools in one account, including text generation, chat, presentation creation, image generation, document translation, and speech-to-text/text-to-speech.
AI & Machine LearningConsumerSaaS
DeepSig develops AI/ML software components and products, including OmniPHY-5G for the 5G RAN and OmniSIG for real-time spectrum awareness, to improve commercial and private wireless communication systems.
AI & Machine LearningDeep TechDefense Tech
PartnerMichael Sutton· solo GP
Feroot discovers and monitors third-party scripts, tags, and trackers on websites to detect malicious or unwanted code and block threats.
CybersecurityEnterprise SoftwareSaaSToronto, CA
Ivan Tsarynny(Founder)inVitaliy Lim(Founder)in
PartnerMichael Sutton· solo GP
Fixify automates common tier 1 IT service desk requests, handling 40+ use cases before they reach IT teams while integrating with the customer's existing ITSM tools.
AI & Machine LearningEnterprise SoftwareSaaS
PartnerMichael Sutton· solo GP
Fleet Device Management is the company behind an open-source device management platform that enrolls millions of laptops, servers, and other devices across Apple, Linux, Windows, and Android.
CybersecurityDeveloper ToolsEnterprise Software
Zach Wasserman(Cofounder)Mike McNeil(CEO)
PartnerMichael Sutton· solo GP
GreyNoise collects primary scanning and exploitation data to provide actionable threat intelligence for cybersecurity defenders.
CybersecurityData & InfrastructureEnterprise SoftwareWashington, US
Andrew Morris(Executive Officer, Director)
PartnerMichael Sutton· solo GP
Grip builds an app inventory and links assets to identities to serve as a technical backbone for AI governance, helping organizations find, trace, contain, and explain points of exposure or risk.
AI & Machine LearningCybersecuritySaaS
PartnerMichael Sutton· solo GP
GroupSense develops patented cyber reconnaissance and threat intelligence technology to help organizations manage the volume of threat intelligence data.
CybersecurityEnterprise SoftwareSaaSArlington, US
Kurtis Minder(Executive Officer, Director, Promoter)Kelly Milan(Executive Officer, Director)Deborah Pearce(Executive Officer)Tom Richards(Executive Officer)Michael Kostoff(Director)Adam Bregenzer(Executive Officer)
PartnerMichael Sutton· solo GP
PartnerMichael Sutton· solo GP
Huntress operates a managed security platform offering endpoint detection and response (EDR), identity threat detection and response (ITDR), managed SIEM, security posture management, and security awareness training, with 24/7 threat hunting and remediation handled by its own SOC team.
CybersecuritySaaS
PartnerMichael Sutton· solo GP
LimaCharlie offers a cloud-native, API-first SecOps Cloud Platform that provides cybersecurity capabilities—such as endpoint protection, log ingestion, detection, automation, and response—as modular, on-demand cloud primitives.
AI & Machine LearningCloud ComputingCybersecurityDeveloper ToolsEnterprise Software
PartnerMichael Sutton· solo GP
New York, US
Michael J Maulick(Executive Officer, Director)Martin Deneroff(Executive Officer)Edwin Upchurch(Executive Officer, Director)Peter Kogge(Executive Officer, Director)Jay Brockman(Executive Officer)
BoardJames Hunt(Director)
PartnerMichael Sutton· solo GP
PartnerMichael Sutton· solo GP
Orca Security offers an agentless cloud security platform that uses its patented SideScanning technology and a unified data model to detect and prioritize risks across cloud infrastructure.
AI & Machine LearningCloud ComputingCybersecuritySaaS
Gil Geron(CEO & Co-founder)Avi Shua(Chief Innovation Officer & Co-founder)Gera Dorfman(Chief Product Officer)Oded Edri(Chief Financial Officer)Rachel Nislick(Chief Marketing Officer)
PartnerMichael Sutton· solo GP
PartnerMichael Sutton· solo GP
RackTop Systems develops BrickStor, a cyberstorage platform that actively defends data against ransomware, insider threats, and data theft through inline inspection and real-time response at the storage layer.
CybersecurityData & InfrastructureDefense TechWashington, US
Eric Bednash(Co-founder)Jonathan Halstuch(Co-founder)
PartnerMichael Sutton· solo GP
runZero (formerly Rumble) is a cyber exposure management platform that provides asset discovery and fingerprinting across IT, OT, IoT, cloud, mobile, and remote environments without agents or credentials.
AI & Machine LearningCybersecuritySaaS
HD Moore
PartnerMichael Sutton· solo GP
SCYTHE is a continuous Adversarial Exposure Validation (AEV) platform that emulates real adversary techniques (mapped to MITRE ATT&CK) against an organization's actual IT, cloud, and OT/ICS environments to validate that detection, alerting, and response controls work.
AI & Machine LearningCybersecurityEnterprise SoftwareSaaSArlington, US
Bryson Bort(Chief Executive Officer)in
PartnerMichael Sutton· solo GP
SecureCircle (Falcon Data Security) provides data security software that discovers and classifies sensitive data and tracks its movement across endpoints, browsers, GenAI workflows, SaaS, and cloud services to detect and stop data theft.
CybersecurityData & InfrastructureSaaS
PartnerMichael Sutton· solo GP
PartnerMichael Sutton· solo GP
Tidal Cyber develops tools and services that help enterprises adopt MITRE ATT&CK framework for threat-informed defense.
CybersecurityEnterprise Software
Rick Gordonin
PartnerMichael Sutton· solo GP
Todyl provides a unified cybersecurity platform for MSPs, IT, and security professionals to defend against threats, manage risk, and maintain compliance.
CybersecurityEnterprise SoftwareSaaSDenver, US
John G. Nellen III(Executive Officer, Director)
BoardSaid Mohammadioun(Director)in
PartnerMichael Sutton· solo GP
PartnerMichael Sutton· solo GP
Valence provides a SaaS and AI security platform that inventories SaaS applications, detects misconfigurations, and manages risks from shadow IT, unmanaged identities, and sensitive data exposure.
AI & Machine LearningCybersecuritySaaS
PartnerMichael Sutton· solo GP
VISO TRUST is an AI-powered third-party risk management (TPRM) platform that helps security teams assess and monitor vendor cyber risk across 3rd, 4th, and nth parties.
AI & Machine LearningCybersecuritySaaS
PartnerMichael Sutton· solo GP
Tenable operates Tenable One, an AI-powered exposure management platform that unifies security visibility across infrastructure, cloud, identity, OT, third-party applications, and AI.
AI & Machine LearningCybersecurityEnterprise Software
PartnerMichael Sutton· solo GP
Portfolio news
latest coverage across their companiesTidal · esgtoday.com · May 29, 2026
Frequently asked questions
- What stage does StoneMill Ventures invest at?
- StoneMill Ventures invests at the Seed, Series A stages.
- What is StoneMill Ventures's typical check size?
- StoneMill Ventures typically writes checks of $100K – $1M.
- What sectors does StoneMill Ventures focus on?
- StoneMill Ventures focuses on Consumer, Cybersecurity, Data & Infrastructure, Enterprise Software, Hardware, SaaS.
- Where is StoneMill Ventures located?
- StoneMill Ventures is headquartered in Washington, US.
- Does StoneMill Ventures lead rounds?
- StoneMill Ventures typically participates in rounds rather than leading them.
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