# Nathan Doctor

> Nathan Doctor is a seed investor at Infinite Capital backing Software and Blockchain. See 54 investments, check sizes, portfolio. Updated Aug 2026.

- Type: Angel Investor
- Fund: [Infinite Capital](https://shizune.co/investors/profile/infinite-capital-b86b)
- Total investments: 54
- Last investment: Jun 2026
- Lead investor: 4%
- Last updated: Aug 2026
- LinkedIn: http://www.linkedin.com/in/nathandoctor
- X (Twitter): http://twitter.com/NathanDoctor
- Website: http://www.nathandoctor.com

Nathan Doctor is a seed investor at Infinite Capital focused on Software and Blockchain. Nathan Doctor is the Founder of Infinite Capital and Co-Founder of Qualified.io and Codewars.com. Infinite Capital is a crypto asset investment firm focused on crypto-native creators and community-led projects. The firm has invested early in many of the top 10 DeFi projects and top 50 cryptocurrencies. Nathan is also an active angel investoracross tech sectors.Qualified.io is a rapidly growing platform for assessing engineering skills, used by Apple, GE, Vimeo, and Zoom. The team also built the developer community, Codewars.com, where over 2 million engineers train their coding skills.

## Round sizes

| Stage | Round size |
| --- | --- |
| Seed | $550k–$9M |
| Series A | $7.5M–$20M |

## Investment focus

### Industry

| Industry | Investments | Share |
| --- | --- | --- |
| Software | 12 | 22% |
| Blockchain | 11 | 20% |
| Cryptocurrency | 7 | 13% |
| Financial Services | 5 | 9% |
| FinTech | 4 | 7% |

67 industries tracked in total.

### Stage

| Stage | Investments | Share |
| --- | --- | --- |
| Seed | 18 | 33% |
| Funding Round | 6 | 11% |
| Series A | 5 | 9% |
| Pre-Seed | 4 | 7% |
| Initial Coin Offering | 4 | 7% |

11 stages tracked in total.

### Country

| Country | Investments | Share |
| --- | --- | --- |
| United States | 27 | 50% |
| Singapore | 3 | 6% |
| Vietnam | 1 | 2% |
| Australia | 1 | 2% |
| South Korea | 1 | 2% |

6 countries tracked in total.

## Investments

| Company | Description | Amount | Stage | Date | Website |
| --- | --- | --- | --- | --- | --- |
| Mach Industries | Mach Industries provides technology solutions for defense systems that are built using techniques for producing and combusting hydrogen from sources found in the field. | $300M | Series C | Jun 01, 2026 |  |
| Radical AI | Radical AI is a technology startup focusing on changing materials science and advanced manufacturing through artificial intelligence. | $55M | Seed | Jul 18, 2025 |  |
| Printr | Printr is a chain-abstracted memecoin launchpad that instantly prints and trades memes. | $2.5M | Pre-Seed | Jan 25, 2025 |  |
| H3X Technologies | H3X Technologies manufactures the lightest electric aircraft propulsion systems in the world to enable sustainable aviation. H3X was founded by Jason Sylvestre, Eric Maciolek, and Max Liben in 2020. | $20M | Series A | Aug 06, 2024 |  |
| H3X Technologies | H3X Technologies manufactures the lightest electric aircraft propulsion systems in the world to enable sustainable aviation. H3X was founded by Jason Sylvestre, Eric Maciolek, and Max Liben in 2020. | $20M | Series A | Aug 06, 2024 |  |
| nftperp | NFTs have become a huge part of web3. Whether you’re in it for the tech, the art, or just to be part of the amazing communities, NFTs are here to stay.However, with nftperp, you can now speculate on the floor prices of NFT projects including Bored Ape Yacht Club, CryptoPunks and more.nftperp was established in January, 2022 in Washington,District of Columbia. |  |  | May 15, 2024 |  |
| nftperp | NFTs have become a huge part of web3. Whether you’re in it for the tech, the art, or just to be part of the amazing communities, NFTs are here to stay.However, with nftperp, you can now speculate on the floor prices of NFT projects including Bored Ape Yacht Club, CryptoPunks and more.nftperp was established in January, 2022 in Washington,District of Columbia. |  | Angel | May 15, 2024 |  |
| Holograph | Holograph enables NFTs to survive and bridge between blockchains while maintaining total data integrity. The company was founded in 2020 and is based in Los Angeles, US. | $3M | Venture - Series Unknown | Apr 29, 2024 |  |
| Apollo ID | Powering the future of hospitality & entertainment globally. | $3M | Pre-Seed | Mar 15, 2024 |  |
| Medallion | Medallion is a company in the media and entertainment industry. Medallion is the future of fans. It was launched in 2020 and is based in New York City, United States. | $13.7M | Series A | Dec 21, 2023 |  |

10 of 54 investments shown.

## Co-investors
- [Infinite Capital](https://shizune.co/investors/profile/infinite-capital-b86b) — VC Fund, 15 deals together
- [Fabric Ventures](https://shizune.co/investors/profile/fabric-ventures) — VC Fund, 4 deals together
- [Liquid 2 Ventures](https://shizune.co/investors/profile/liquid2-ventures) — VC Fund, 4 deals together
- [Lockheed Martin Ventures](https://shizune.co/investors/profile/lockheed-martin-ventures) — VC Fund, 4 deals together
- [Metaplanet](https://shizune.co/investors/profile/metaplanet-holdings) — VC Fund, 4 deals together
- [Tamar Capital](https://shizune.co/investors/profile/tamar-capital) — VC Fund, 4 deals together

## About Infinite Capital

VC Fund · Fountain Valley, United States

Infinite Capital invests in generational innovation, with a focus on decentralized networks and deep tech.

1 contacts available at Infinite Capital.

| Name | Title | Profile |
| --- | --- | --- |
| Nathan Doctor | Founder | https://shizune.co/investors/profile/nathan-doctor |

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## FAQ

### What does Nathan Doctor invest in?

Nathan Doctor invests primarily in Software, Blockchain and Cryptocurrency startups, most often at Seed and Funding Round stage. Most of the 54 investments tracked by Shizune back companies in United States. The Investment Focus section breaks down every industry, stage and country in the portfolio.

### What is Nathan Doctor's check size?

Nathan Doctor typically joins rounds of $550k–$9M at Seed and $7.5M–$20M at Series A. These ranges are 10th–90th percentile round sizes calculated from confirmed public funding rounds, so they are a realistic guide to the rounds Nathan Doctor participates in.

### When did Nathan Doctor last invest?

The most recent investment recorded for Nathan Doctor closed in Jun 2026. Shizune tracks 54 investments in total for this profile, including round sizes, stages and portfolio companies, all sourced from confirmed public funding rounds and refreshed monthly.

### Is Shizune's investor data accurate?

Yes — every stat on this profile is calculated from confirmed public funding rounds monitored across hundreds of sources since 2020. This profile was last refreshed in Aug 2026 and is updated monthly. Spotted something off? Use the “Suggest an edit” link near the top of the page.

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