Typical seed round size for biotech startups in Boston
Based on 37 Form D filings by Boston biotech issuers at seed stage, filed Oct 2024 – Sep 2026. Updated monthly. Change any segment to compare.
The numbers
- Median seed raise: $4.2M
- Middle half of rounds: $1.8M – $6.7M
- Filings in sample: 37
- Rounds under $1M: 11%
- Rounds over $5M: 30%
- Updated Sep 2026
Read this number carefully
Form D undercounts small SAFE rounds and rounds that rely on other exemptions. Treat the median as a ceiling for "typical", not a target.
Compare segments
Biotech · Seed · Bay Area ($3.8M)
Biotech · Seed · San Diego ($1.9M)