Fundraising Fox

Stephen Marcus

Investor

General Partner at Riot Ventures · Board director at Shield AI

Los Angeles, California

Writes $3M checks · typically $1.5M

About

Stephen Marcus, a six-time founder/CEO with 20+ years building large-scale wireless networks and datacenters, brings deep infrastructure and hardware expertise and a record of frontier bets that produced IPOs.

Contact· self-published, not guessed

Invests in

AI & Machine LearningCybersecurityDeep TechDefense TechHardwareLogistics & Supply ChainRoboticsSpace Tech

Board director at Shield AI

Intro paths

→

In turn, Stephen can intro founders to Shield AI's investors below.

Shield AI's investors · 42

645 VenturesNew York · $1M – $5M checksAdvaita CapitalBostonAdvent InternationalBoston · $1.1B checks · since 2025Alpha PartnersNew York · $3M – $10M checksAltra VentureNew York City · $500K – $25M checksAndreessen HorowitzMenlo Park · $500K – $50M checks · since 2022Beyond CapitalSan DiegoBlackstonesince 2025Bloomberg BetaSan Francisco · $25K – $1M checksBooz Allen VenturesBrave CapitalSan RafaelBreyer CapitalAustin · $500K – $10M checks · since 2022Brighter CapitalCupertino · $25K – $100K checksCenter15 CapitalLos AngelesChaos VenturesNew YorkCortado VenturesOklahoma CityCraft VenturesSan Francisco · $50K – $50M checksDisruptiveDallas · since 2025Dorm RoomBrooklyn · $90K – $250K checksE1 VenturesSan FranciscoFounder CollectiveCambridgeHomebrewBurlingame · $100K – $500K checks · since 2022Inertia VenturesNew York · $2M checksInflection VenturesNew YorkJuniperoMiamiK2 GlobalSingaporeKinled HoldingHong KongLevel VenturesSunny Isles BeachManhattan WestLos AngelesNearingpoint Venture Partners Inc.TorontoPoint72 VenturesNew York · $1M – $75M checks · since 2022Prime Movers LabJackson · $2M – $30M checks · since 2025R7 PartnersChicago · $100K – $5M checksRiot VenturesVenice · $3M checks · since 2025Riverbend CapitalWashingtonRosecliff VenturesNew York City · $500K checksSnowpointPalm Beach · since 2026SnowPoint VenturesWest Palm Beach · since 2025Stack CapitalTorontoU.S. Air Forcesince 2019WealthUnion$10K checksWP Global PartnersChicago · $5M – $25M checks

Co-founders at Shield AI

BTBrandon Tseng
Brandon TsengPresident & Co-Founder
RTRyan Tseng
Ryan TsengPresident, Co-Founder & Chief Strategy Officer
ARAndrew Reiter
Andrew ReiterCo-Founder

Experience

  1. Riot VenturesCo-Founder & General Partnercurrent2015 — presentLos Angeles Metropolitan Area
  2. EnduroSatBoard Membercurrent2025 — present
  3. Blue Water AutonomyBoard Membercurrent2025 — present
  4. Nodal NetworksBoard Membercurrent2024 — present
  5. Valar AtomicsBoard Membercurrent2023 — presentLos Angeles, California, United States
  6. Mango IncBoard Membercurrent2022 — present
  7. KindoBoard Membercurrent2022 — presentLos Angeles, California, United States
  8. Shield AIBoard Membercurrent2019 — presentSan Diego County, California, United States
  9. Toast, Inc.Investorcurrent2019 — presentGreater Boston
  10. MIT Deshpande CenterCatalystcurrent2016 — presentCambridge, MA
  11. Okta, Inc.Angel Investorcurrent2010 — present
  12. StripeAngel Investorcurrent2014 — present
  13. Matchbox, Inc.Founder & CEO2011 — 2015Greater Boston
  14. MIT Sloan School of ManagementMember of Admissions Committee2009 — 2011
  15. Invincea, Inc.Board Observer2008 — 2011
  16. New Atlantic VenturesVenture Partner2008 — 2011
  17. Marcus CompaniesCEO2001 — 2010
  18. SprintMergers and Acquisitions Consultant2000 — 2007

Skills & more

Strategy9Management4Leadership3Enterprise Software11SaaS2Venture Capital45Start-ups99Mergers10Wireless5Mobile Devices26Entrepreneurship59Cloud Computing7
+12 moreE-commerceMobile ApplicationsMergers & AcquisitionsTelecommunicationsProduct ManagementProduct MarketingProgram ManagementStrategic PartnershipsCompetitive AnalysisAngel InvestingNetworkingAnalytics

Languages English · Spanish

From Stephen's professional profile.

Investments

Board seats

Blue Water AutonomyEndurosatKindoMangoShield AIValar Atomics

Per the firm's website.

Colleagues at Riot Ventures

Meghan Moreland
Investor at Riot Ventures
Will Coffield
Co-founder and General Partner at Riot Ventures

Frequently asked questions

Who is Stephen Marcus?
Stephen Marcus, a six-time founder/CEO with 20+ years building large-scale wireless networks and datacenters, brings deep infrastructure and hardware expertise and a record of frontier bets that produced IPOs.
Where does Stephen Marcus work?
Stephen Marcus is General Partner at Riot Ventures and Board director at Shield AI.
What does Stephen Marcus invest in?
Stephen Marcus invests in AI & Machine Learning, Cybersecurity, Deep Tech, Defense Tech, Hardware, Logistics & Supply Chain, Robotics, Space Tech.
What check size does Stephen Marcus write?
Stephen Marcus typically writes checks of $3M.
What boards does Stephen Marcus sit on?
Stephen Marcus holds tracked board seats at Blue Water Autonomy, Endurosat, Kindo, Mango, Shield AI, Valar Atomics.
Where did Stephen Marcus go to school?
Stephen Marcus studied at MIT Sloan School of Management (MBA, Entrepreneurship & Venture Capital); Worcester Polytechnic Institute (BS).

Same school

Also attended MIT Sloan School of Management592

Doug LeonePartner at Sequoia Capital; former Global Managing PartnerHemant TanejaCEO & Managing Director of General CatalystBrad FeldCo-founder of Foundry and TechstarsChris MorrisProcess Specialist, Exit Readiness at Mayfair Equity PartnersBirgitteInvestor at InvestinorOlaInvestor at Investinor

+ 586 more

Also attended Worcester Polytechnic Institute42

Steve VassalloInvestor at Foundation CapitalAbe MurrayGeneral Partner at AlleyCorpCharles White, Ph.D.Principal at Illumina VenturesJiong MaInvestor at Phoenix Venture PartnersJill GoldsteinPrincipal at Vida VenturesGregor KevrekianPartner at Healthier Capital

+ 36 more

Shared employers

Also worked at Blue Water Autonomy2

Seth WinterrothPartner and Head of Policy at Eclipse VenturesStephen RodriguezOperating Partner at DCVC (Data Collective)

Also worked at Valar Atomics7

Abe MurrayGeneral Partner at AlleyCorpKim-Mai CutlerInvestor at Initialized CapitalJean WeillAssociate at C4 VenturesDoug PhilipponePartner & Co-Founder at SnowpointHisham ElhaddadManaging Partner at HOF CapitalPhil BradyManaging Partner at GoAhead Ventures

+ 1 more

Also worked at Stripe182

Hemant TanejaCEO & Managing Director of General CatalystMatt HuangCo-founder and Managing Partner at ParadigmLuciana LixandruPartner at Sequoia CapitalPatrick CollisonCo-founder & CEO of StripeJohn CollisonCo-founder & President of StripeGreg BrockmanCo-founder & President of OpenAI

+ 176 more

Also worked at MIT Sloan School of Management111

Isabelle StyslingerSenior Associate, Rise of the Rest at RevolutionNoubar AfeyanInvestor at Flagship PioneeringIsabelle TashimaSr. Associate at Volition CapitalAkanksha MehtaInvestor at TRANSFORMATION CAPITALRandy CohenHarvard Business School Professor at FemHealth VenturesAqil PashaVice President at Jump Capital

+ 105 more