Sean Cai, Investor at Costanoa Ventures is an active investor based in San Francisco, California. This profile covers what Sean Cai backs, at which stage, and how founders can reach out in 2026.
Sean Cai is an investor at Costanoa Ventures, with a focus on data and reinforcement learning.
Sean Cai invests in Developer Tools & Data and Artificial Intelligence, typically at Seed and Series A.
- Investor type
- VC
- Stages
- SeedSeries A
- Invests in
- Developer Tools & DataArtificial Intelligence
- Location
- San Francisco, California
- Typical check
- $625K
How to reach Sean Cai
Angels and operators like Sean Cai 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.
Reach active investors like this one
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. How this data is built.
Cite this page
Round Funded. "Sean Cai." Round Funded investor database, updated November 3, 2026.
Stable URL, it will not change: https://www.roundfunded.com/en/investor/sean-cai
Frequently Asked Questions
Who is Sean Cai?
Sean Cai, Investor at Costanoa Ventures is an active investor based in San Francisco, California. Sean Cai invests in Developer Tools & Data and Artificial Intelligence, typically at Seed and Series A.
What does Sean Cai invest in?
Sean Cai invests in Developer Tools & Data and Artificial Intelligence, typically at Seed and Series A. Match your sector and stage, then reach out with a personalized pitch.
What stage does Sean Cai invest at?
Sean Cai typically invests at Seed and Series A. Lead with traction that fits the stage when you reach out.
What is Sean Cai's typical check size?
Sean Cai typically writes checks around $625K. Use it as a signal for whether your raise fits their stage.
How do founders reach investors like this?
Round Funded lists active investors with verified, professional contact details for signed-up founders. Filter by sector, stage and location, then send a personalized pitch from your own inbox.
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.