Sunstone Partners is a growth-oriented private equity firm founded in 2015 and based in San Mateo, California. The firm invests in AI- and technology-enabled services and software companies through majority and minority transactions, typically targeting businesses with $20M+ in revenue and 20%+ annual growth.
Average disclosed round size is $26.2M (across 29 rounds with reported amounts).
Portfolio
33
Fund Size
$925M
Top Stage
Series A
Last 12 Mo
1
Team
Portfolio Breakdown
Stage Distribution
Sector Distribution
Investment Activity
DealsAvg Round Size
Portfolio
43 investments
| Company | Round | Amount | Date |
|---|---|---|---|
 Kynexis | Series A | — | Aug 2026 |
 ProgenyHealth | Growth | — | May 2025 |
 OSF Digital | Series C | $100M | Apr 2022 |
| QQwinix | Growth | — | May 2021 |
| CCloudbakers | Growth | — | Dec 2020 |
 TravelPerk | Series C | $60M | Jul 2019 |
 Peakon | Series B | — | Mar 2019 |
 White Star Capital | Series B | $11M | Feb 2019 |
| GGalecto Biotech | Series C | — | Oct 2018 |
 Taster | Seed | $4M | Jun 2018 |
| TravelPerk | Series B | — | Apr 2018 |
| Peakon | Series B | $22M | Feb 2018 |
 Aula | Seed | $4.2M | Jan 2018 |
| IInboard | Series A | $8M | Nov 2017 |
 Mojiworks | Series A | — | Nov 2017 |
 GetYourGuide | Series D | $75M | Nov 2017 |
| PPrexton Therapeutics | Series B | — | Feb 2017 |
| IInboard | Seed | $11.7M | Jan 2017 |
| PPrexton Therapeutics | Series B | $31M | Jan 2017 |
| OOnica | Unknown | $20M | Jan 2017 |
 Neo4J | Series D | $36M | Nov 2016 |
| FFreespee | Series B | — | Nov 2016 |
 Natural Cycles | Series A | $6M | Jul 2016 |
| TravelPerk | Series A | $7M | Jun 2016 |
| Peakon | Series A | — | Jan 2016 |
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Top Co-Investors
Ysios Capital7 shared
Sunstone Life Science Ventures7 shared
Sunstone6 shared
Balderton Capital5 shared
Spark Capital4 shared
General Catalyst4 shared
Idinvest Partners4 shared
M Ventures4 shared
Forbion4 shared
Phoenix Court Group3 shared
Upfront Ventures3 shared
Lifeline Ventures3 shared
Bristol Myers Squibb3 shared
Novo Holdings A/S3 shared
Hadean Ventures3 shared
KKR2 shared
Battery Ventures2 shared
Nokia Ventures2 shared
Target Global2 shared
Felix Capital2 shared
Last updated: 20 October 2026