About
Guy Horowitz has 22 years in cybersecurity and infrastructure, founded Deutsche Telekom’s investment office in Israel, and speaks globally on cyber risk while bridging European, Israeli and US security ecosystems.
Invests in
CybersecurityDeveloper Tools
Experience
- 33N VenturesPartnercurrent2025 — presentPalo Alto, CA
- Bold SecurityInvestorcurrent2026 — present
- AponoInvestorcurrent2025 — present
- Daylight SecurityInvestorcurrent2025 — present
- Noma SecurityInvestorcurrent2025 — present
- HuskeysInvestorcurrent2025 — present
- Glide IdentityInvestorcurrent2025 — present
- AsteliaInvestorcurrent2025 — present
- MontoInvestorcurrent2024 — present
- NominalInvestorcurrent2023 — present
- Mesh SecurityInvestorcurrent2024 — present
- DigmaInvestorcurrent2023 — present
- CynomiInvestorcurrent2022 — present
- ESH.vcManaging Partnercurrent2023 — present
- DremioInvestorcurrent2022 — present
- EverAfterInvestorcurrent2023 — present
- Opus SecurityInvestor2023 — 2025
- Siemplify (Now Part of Google Cloud)Investor2015 — 2023
- Lightspin (Acquired by Cisco)Investor2021 — 2023
- DTCPPartner, Growth Equity2015 — 2023Menlo Park, CA
- AxoniusInvestor2021 — 2023
- PerimeterXBoard Observer2019 — 2023
- AppsFlyerInvestor2016 — 2023
- SafeBreachBoard Member2016 — 2023San Francisco Bay Area
- GuardicoreInvestor2019 — 2021
- MorphisecBoard Observer2015 — 2021
- Utilis Ltd.Board Advisor2014 — 2021
- German-Israeli Chamber of Industry & Commerce - AHK IsraelDirector2014 — 2020
- Dynamic Yield by MastercardBoard Observer2017 — 2019
- Fireglass - Acquired by Symantec (May 2017)Board Observer2016 — 2017
- Replay Technologies - Acquired by Intel (March 2016)Board Observer2015 — 2016
- Deutsche Telekom AGVice President, Business Development & Venturing; GM Israel2012 — 2015Tel Aviv, Israel
- SWAN - The Smart Water Networks ForumChairman2010 — 2013London, United Kingdom
- TaKaDuVice President of Marketing & Business Development2010 — 2012
- Gemini Israel FundsPrincipal2008 — 2010Herzliya, Tel Aviv District, Israel
- moduAVP, Marketing Strategy2008
- MicrosoftDirector of Product Marketing, Telecom Products2007 — 2008
- Gemini Israel FundsAssociate2004 — 2007
- Followap Inc.VP of Product Marketing2001 — 2004
- Neustar, Inc.Head of Product Management2001 — 2003
Skills & more
Private Equity2Negotiation1Investment Banking1Due Diligence1Deal StructuringCorporate Strategy1Analytical SkillsPresentationsInvestment Strategies1Executive Relationships1DealsCompetitive Landscape
+12 more
C-LevelCorporate DevelopmentCorporate Partnership DevelopmentSaaSProduct ManagementTelecommunicationsProject ManagementProduct MarketingEnterprise SoftwareSoftware as a Service (SaaS)StrategyStrategic PlanningLanguages English · French · German · Hebrew · Italian
From Guy's professional profile.
Colleagues at 33N
Achiad Avivi
Expert Advisory Board — Founder at LAS security at 33N
Adam Frankl
Expert Advisory Board — Partner at Alchemist Accelerator at 33N
Alina Medentsy
VC Operations Analyst at 33N
André Azevedo
Expert Advisory Board — CEO at Ancoris at 33N
Artur Monteiro
Technologist In Residence at 33N
Ayman Hammoudeh
Expert Advisory Board — Venture Advisor at 33N
Brian Nesmith
Strategic Committee — Founder & Executive Chairman at Arctic Wolf at 33N
Carlos Alberto Silva
Managing Partner at 33N
Network1
Investors connected to Guy in public investor directories — a warm-intro map.
Frequently asked questions
- Who is Guy Horowitz?
- Guy Horowitz has 22 years in cybersecurity and infrastructure, founded Deutsche Telekom’s investment office in Israel, and speaks globally on cyber risk while bridging European, Israeli and US security ecosystems.
- Where does Guy Horowitz work?
- Guy Horowitz is Venture Partner at 33N.
- What does Guy Horowitz invest in?
- Guy Horowitz invests in Cybersecurity, Developer Tools.
- What check size does Guy Horowitz write?
- Guy Horowitz typically writes checks of $4.3M – $13M.
- Where did Guy Horowitz go to school?
- Guy Horowitz studied at University of Haifa (MBA, Business Administration); Technion - Israel Institute of Technology (Entrepreneurship program); University of Haifa (BA, Economics).
Same school
Also attended University of Haifa40
Roi Bar-KatManaging Director at Intel CapitalShimon TsentsiperVenture Partner at Key1 CapitalTamir CarmiVenture Partner at PICO Venture PartnersDani GoldsherPartner and CFO at TriventuresAmir FaintuchVenture Partner at PitangoYotam DaganCo-Founder, Advisor at Vetted Accelerator
+ 34 more
Also attended Technion - Israel Institute of Technology163
Roi Bar-KatManaging Director at Intel CapitalGil GorenPartner at 83NorthOren YungerInvestor at GGV CapitalGordon DaughertyCo-Founder & Chairman at Capital FactoryBoaz PeerManaging Director, Israel & Europe at Qualcomm VenturesGal GitterPartner at Alpha Partners
+ 157 more
Also attended Rutgers University120
Jigar RaythathaInvestor at Third Rock VenturesRobin LiInvestor at GGV CapitalDominique LittleGovernment Affairs Lead at ParadigmGanesh PersadVice President & Chief Information Officer at Flare Capital PartnersMark FieldsInvestor at Alsop Louie PartnersBasil AlomaryPrincipal, Head of Research & Growth Strategy at Stripes
+ 114 more
Shared employers
Also worked at Bold Security5
Also worked at Huskeys2
Also worked at Siemplify (Now Part of Google Cloud)3
Also worked at Microsoft1,188
Reid HoffmanCo-founder of LinkedIn; Partner at GreylockGarry TanPresident & CEO of Y CombinatorNat FriedmanCo-lead of Meta Superintelligence Labs; co-founder of NFDGKai-Fu LeeChairman of Sinovation Ventures and CEO of 01.AIBill GatesCo-founder of Microsoft; Chair of the Gates FoundationMike KriegerCo-founder of Instagram; Chief Product Officer at Anthropic
+ 1,182 more