Seth Hallen
Founder | Managing Partner at Hallstone Ventures
Los Angeles, California
Seth Hallen, Founder | Managing Partner at Hallstone Ventures is an active investor based in Los Angeles, California. This profile covers what Seth Hallen backs, at which stage, and how founders can reach out in 2026.
Seth Hallen is the Founder and Managing Partner of Hallstone Ventures, a seed fund investing in AI infrastructure for the media, entertainment, and advertising economy.
- Investor type
- VC
- Stages
- Seed
- Invests in
- Media & ContentMarketing & AdTechArtificial Intelligence
- Location
- Los Angeles, California
- Typical check
- $250K
How to reach Seth Hallen
Angels and operators like Seth Hallen reply to specific, personalized notes that show real traction, not mass blasts. Build a verified list, write a note that fits their thesis, and track replies, all on Round Funded.
Connect with Seth Hallen
About this profile
This profile is part of Round Funded, an investor database and outreach platform for founders. It covers 60,000+ active VCs, angels, family offices and accelerators with verified contacts, lets you send pitches from your own Gmail, and includes a free Data Room for your raise.
Frequently Asked Questions
What does Seth Hallen invest in?
Seth Hallen invests in Media & Content, Marketing & AdTech and Artificial Intelligence, typically at Seed. Match your sector and stage, then reach out with a personalized pitch.
What stage does Seth Hallen invest at?
Seth Hallen typically invests at Seed. Lead with traction that fits the stage when you reach out.
What is Seth Hallen's typical check size?
Seth Hallen typically writes checks around $250K. Use it as a signal for whether your raise fits their stage.
How do I contact Seth Hallen?
Unlock Seth Hallen's verified email on Round Funded and send a personalized pitch. We surface only deliverable contacts so your outreach lands.
What is Round Funded?
Round Funded is an investor database and outreach platform for startup founders. It lists 60,000+ active investors with verified contacts, filtered to recent investment activity, and lets founders send personalized pitches from their own Gmail, track replies, and share a free Data Room. Round+ starts at $99 per month with a 3-day trial.