Mark Josephson

Active Investor

Entrepreneur in Residence (EIR) at Yale Ventures

Bethesda, Maryland

Mark Josephson, Entrepreneur in Residence (EIR) at Yale Ventures is an active investor based in Bethesda, Maryland. This profile covers what Mark Josephson backs, at which stage, and how founders can reach out in 2026.

Mr. Mark Josephson is a Co-Founder and serves as Chief Executive Officer and Board Member at Castiron. Mr. Josephson is an Angel Investor. He served as Advisor at DIMO. He also served as Chief Executive Officer at bitly. He served as Chief Technology Officer at Mediaplex. He served as Chief Executive Officer at Outside.In.

Investor type: AngelAccelerator
Stages: Early Stage VenturePre SeedSeedLate Stage Venture
Invests in: Healthcare & BiotechBiotech & PharmaMedTech & Medical DevicesSaaS & EnterpriseConsumer & RetailIoT & Connected DevicesMobility & LogisticsSupply Chain & Logistics
Location: Bethesda, Maryland
Typical check: $375K
Past investments: 11

Notable investments

AxilionDIMO (Business/Productivity Software)CarteavAlumnifireOsmosis (Educational Software)SwftOnward DeliveryBrief.aiZypp ElectricMoodifyLittle Peconic

How to reach Mark Josephson

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Frequently Asked Questions

What does Mark Josephson invest in?

Mark Josephson invests in Healthcare & Biotech, Biotech & Pharma, MedTech & Medical Devices and SaaS & Enterprise, typically at Early Stage Venture, Pre Seed, Seed and Late Stage Venture. Match your sector and stage, then reach out with a personalized pitch.