Investors / United States / S3 Ventures
S3 Ventures
Venture capital · Austin, TX, United States · North America
S3 Ventures is a venture capital firm backed by a single philanthropic limited partner, which it says allows it to invest without the constraints of traditional fundraising. It leads early-stage rounds and has backed more than 75 companies.
Invests inHealthcare & BiotechFintech
In its own wordsbusiness technologyhealthcare technologysoftwaremedical devicesit infrastructuredeveloper tools
Your fit with S3 Ventures
Four questions about your startup
See how your round matches what it backs, point by point.
Or find every investor that fitsS3 Ventures lists 23 checked portfolio companies on its own site and is named in 24 funding rounds, 15 of them as lead. Its most frequent entry is Series A, 38% of the companies with a known first round. Its largest themes are Healthcare & Biotech (24%), Fintech (24%) and AI & Machine Learning (15%). 91% of its companies are based in United States. It invests most often alongside BioStar Capital, Correlation Ventures and NC Tweener Fund.
Counts come from funding rounds that name S3 Ventures, complete from mid-2025: earlier rounds appear only when they were reported later. Round amounts and full round histories are on Fundup AI.
Entry stage
share of companies by the stage of its first roundShow as a table
| Value | |
|---|---|
| Pre-seed | 0% |
| Seed | 21% |
| Series A | 38% |
| Series B | 17% |
| Growth | 25% |
Activity by year
rounds it joined, last 10 yearsShow as a table
| Total | Rounds it led | |
|---|---|---|
| '17 | 0 | 0 |
| '18 | 0 | 0 |
| '19 | 0 | 0 |
| '20 | 0 | 0 |
| '21 | 0 | 0 |
| '22 | 0 | 0 |
| '23 | 0 | 0 |
| '24 | 0 | 0 |
| '25 | 7 | 5 |
| '26 | 17 | 10 |
Investor profile
percentile among all firmsShow as a table
| Measure | Percentile of all firms | Value |
|---|---|---|
| Portfolio size | 55th | 22 companies |
| Recent activity | 98th | 20 rounds in 12 months |
| Early stage | 58th | 21% of entries at pre-seed or seed |
| Evidence | 52th | 0% of companies confirmed by a round |
| Sector focus | 29th | 24% in its largest sector |
| Reach | 58th | 3 countries |
Investment themes
share of its checked companiesThis firmAll checked companies
Show as a table
| This firm | All checked companies | |
|---|---|---|
| Healthcare & Biotech | 24% | 15% |
| Fintech | 24% | 12% |
| AI & Machine Learning | 15% | 18% |
| Space & Defense | 9% | 3% |
| Enterprise Software | 9% | 8% |
| Cybersecurity | 3% | 4% |
| Developer Tools | 3% | 0% |
| Real Estate & Construction | 3% | 3% |
Invests most often with
firms sharing its portfolio companiesShow as a table
| Share | |
|---|---|
| BioStar Capital | 2 |
| Correlation Ventures | 2 |
| NC Tweener Fund | 2 |
| Next Coast Ventures | 2 |
| Santé Ventures | 2 |
| 100KM VC | 1 |
| 415 Capital | 1 |
| Advisors.Fund | 1 |
Its portfolio companies
where they are based, and what their own sites showSite status
- Site answers23100%
- No longer answers00%
- Points to another company00%
- Parked or sold domain00%
A site that stops answering three checks in a row is counted as no longer answering; that is not proof of closure. A site that points to another company is often an acquisition.
Co-investor network
who it backs companies with, and who they back togetherCompare S3 Ventures head to head
portfolio size, rounds, entry stages, themes and the companies both backThree or more firms at once: portfolio overlap.
Recent portfolio activity
when companies last raised with S3 Ventures| Date | Company | Stage |
|---|---|---|
| 8 Oct 2026 | Series C+ | |
| 26 Aug 2026 | Series A Led | |
| 20 Aug 2026 | Series A Led | |
| 18 Aug 2026 | Series A Led | |
| 11 Aug 2026 | Series C+ Led | |
| 4 Aug 2026 | Series A Led | |
| 28 Jul 2026 | Series A | |
| 16 Jul 2026 | Series B Led |
Round details for S3 Ventures
Amounts, full round histories and every co-investor in S3 Ventures' rounds are on Fundup AI. VCinfo covers investors and their portfolios.
Portfolio
23 companies checked against their own sites| Company | What it does | Themes | First round with it | Evidence |
|---|---|---|---|---|
| Advanced NanoTherapies develops and manufactures drug-coated balloons for treating coronary and peripheral artery diseases. | Healthcare & Biotech | Jun 2026Series B | Funding round | |
| Arpio provides disaster recovery services for cloud and agent-based applications | Space & DefenseCybersecurity | Jun 2026Series A | Funding round | |
| Avtal helps collection agencies increase liquidation rates without adding headcount. | FintechDeveloper Tools | Mar 2026Seed | Funding round | |
| The company provides a leasing operating system for property managers | Real Estate & ConstructionFintech | Aug 2026Series A | Funding round | |
| Braincheck provides a digital platform for cognitive assessment and care planning | Healthcare & Biotech | Feb 2026Series A | Funding round | |
| The company provides a platform for contractors to hire and manage electricians | Human ResourcesEducation | Jul 2026Series A | Funding round | |
| Buzz Solutions provides software to help utilities manage and analyze their energy infrastructure using artificial intelligence and visual data. | AI & Machine LearningE-commerce & Marketplaces | Aug 2026Series A | Funding round | |
| Cloverleaf AI provides sales intelligence for businesses selling to government agencies | AI & Machine LearningEnterprise Software | Aug 2026Series A | Funding round | |
| Earlytrade provides a platform for early payment negotiation in the construction industry | FintechConsumer | Jun 2026Series A | Funding round | |
| Endovascular Engineering develops medical devices for removing blood clots | Healthcare & Biotech | Apr 2026Series C+ | Funding round | |
| Folia Health is a health tracking app that helps people with chronic conditions track their health and provides valuable structured data insights to support research and personalized care. | Healthcare & Biotech | Oct 2025Series A | Funding round | |
| The company allows users to invest in US and Saudi stocks through its platform. | FintechFintech | Feb 2026Seed | Funding round | |
| Oct 2025Series C+ | Funding round | |||
| The company develops and provides a system for prostate care that combines imaging and therapy | Healthcare & Biotech | Aug 2026Series A | Funding round | |
| The company develops and provides robotic microsurgery systems and instruments for surgeons to perform complex procedures with greater precision and control. | Healthcare & Biotech | Oct 2026Series C+ | Funding round | |
| Nestimate provides software and services to help implement and manage retirement income solutions in defined contribution plans. | FintechFintech | Sept 2025Seed | Funding round | |
| Mythic develops and manufactures artificial intelligence products, including analog processing units and AI platforms, for various industries such as automotive, robotics, and enterprise. | AI & Machine LearningSpace & Defense | Dec 2025Series C+ | Funding round | |
| RapidPulse Inc is involved in clinical trials, including a pivotal ischemic stroke study. | Healthcare & Biotech | Jul 2026Series B | Funding round | |
| The company provides a platform for usage-based billing and governance on a real-time ledger. | FintechSpace & Defense | Apr 2026Seed | Funding round | |
| The company provides revenue intelligence for technical sales | AI & Machine LearningEnterprise Software | Dec 2025Seed | Funding round |
About this data
site last read 5 Nov 2026- Site
- s3vc.com
- Last read
- 5 Nov 2026
- Watching since
- 5 Nov 2026
- Rounds since
- 15 Sept 2025
- Companies checked
- 23
Rates come from what VCinfo has observed since observation_start. Firms tend to remove companies that closed, so early rates understate reality. A company leaving a portfolio page does not mean it closed or exited. An unreachable site means our checks failed, nothing more.
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