The 2025 Playbook for Early Stage Health Tech Angel Investing: What Carta’s Latest Data Tells Us About Founder Equity, Team Dynamics, and SAFE Financing

Disclaimer: The views and opinions expressed in this essay are solely my own and do not reflect the views, opinions, or positions of my employer or any affiliated organizations.

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If you are interested in joining my generalist healthcare angel syndicate, reach out to trey@onhealthcare.tech or send me a DM. Accredited investors only.

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Table of Contents

Abstract

Introduction

Founding Team Composition and the Solo Founder Trend

Founder Equity Splits and the Economics of Partnership

The Cofounder Breakup Problem

Founder Vesting and the Dangerous Game of Unprotected Equity

The Advisor Equity Question

Early Employee Equity and the First Ten Hires

Employee Option Pools and Strategic Dilution Management

Hiring Patterns at the Earliest Stages

SAFE Financing Mechanics in 2025

Valuation Caps and the New Normal

Seed Round Economics and Founder Ownership

AI’s Impact on Fundraising Dynamics

Founder Ownership Trajectories to Exit

Portfolio Construction Implications for Health Tech Angels

Conclusion

Abstract

Carta’s latest dataset provides the most comprehensive look yet at early stage startup economics, covering everything from founding team structures to SAFE financing mechanics. For health tech angel investors, this data reveals several critical insights. Solo founding has increased to 35 percent of all new startups in 2024, up from 17 percent in 2015, though VC-backed companies still skew toward multiple cofounders at 83 percent. Equal equity splits among cofounders have become more common, reaching nearly 46 percent for two-founder teams in 2024. About 24 percent of two-founder VC-backed teams lose a cofounder by year four, highlighting the importance of proper vesting schedules. Median advisor equity has dropped to 0.25 percent at preseed and 0.11 percent at seed. The first employee typically receives 1.54 percent equity, declining rapidly to 0.48 percent by the fifth hire. Founders are delaying their first three hires substantially, with median time to first hire increasing from 320 days in 2019 to 476 days in 2024. Post-money SAFEs have become the dominant structure at 88 percent of preseed deals by 2025. Valuation caps only (without discount) now represent 61 percent of all SAFEs, up from 41 percent in 2020. Healthcare-relevant sectors show significant variance, with median seed valuations ranging from around 14M for traditional software to over 20M for AI companies. Median founder ownership drops from 56 percent after seed to 36 percent after Series A and 23 percent after Series B. For angel investors building health tech portfolios, these patterns suggest focusing on teams with proper four-year vesting, appropriate option pool sizing (10 percent at seed seems standard), realistic valuation expectations relative to subsector, and capital efficiency that allows meaningful founder retention through multiple rounds.

Introduction

Peter Walker and the team at Carta have been doing the lord’s work for years now, publishing increasingly detailed analyses of startup equity structures based on their massive dataset of cap tables. Their latest release is particularly rich, covering founding team dynamics, equity allocation patterns, SAFE financing mechanics, and ownership trajectories from incorporation through later stage rounds. For those of us investing at the angel and preseed stages in healthcare, this data is pure gold. It lets us benchmark what we’re seeing in our own deal flow against broader market patterns and, more importantly, helps us identify when a founding team is setting themselves up for problems down the road.

The healthcare technology landscape has evolved considerably over the past decade. We’ve moved from a world where most digital health startups were consumer-facing apps or basic workflow tools to a much more sophisticated ecosystem spanning infrastructure plays, clinical AI, specialty SaaS, and novel care delivery models. Each of these subsectors has different capital requirements, team composition needs, and typical ownership structures. Understanding how equity gets allocated and diluted in the earliest days of a company directly impacts whether founders remain motivated through the long, difficult journey to product-market fit and eventual exit.

What follows is a detailed analysis of Carta’s findings with specific application to health tech angel investing. I’ve tried to pull out the patterns that matter most for portfolio construction and due diligence while maintaining the casual, data-driven approach that I think works best for this audience. If you’re writing checks between 10k and 100k into very early stage healthcare companies, this is meant to give you a framework for evaluating team structures and equity splits that you can apply immediately.

Founding Team Composition and the Solo Founder Trend