# Bill Bartee

> Bill Bartee is a Series A investor at Main Sequence Ventures (Sydney) backing Software and SaaS. See 27 investments, check sizes, portfolio. Updated Aug 2026.

- Type: Angel Investor
- Fund: [Main Sequence Ventures](https://shizune.co/investors/profile/main-sequence-ventures)
- Location: Sydney, Australia
- Total investments: 27
- Last investment: Jul 2025
- Lead investor: 48%
- Last updated: Aug 2026
- LinkedIn: https://www.linkedin.com/in/billbartee/
- X (Twitter): https://twitter.com/wbartee
- Website: https://x.com/wbartee

Bill Bartee is a co-founder and Managing Director of Blackbird Ventures and of Southern Cross Venture Partners. He has co-founded several successful companies. At Southern Cross Bill focuses on early-stage software, security, and internet companies. From 1997 to 2001, he helped build and lead the early stage investing for Macquarie TechnologyVentures (MTV), a balanced venture fund focused on software, telecommunications, internet and life sciences. At MTV, Bill led investments in several market leaders including Altium (ASX: ALU), LookSmart (NASDAQ: LOOK), Seek (ASX: SEK), Telera (acquired by Alcatel), and onebox (NASDAQ: OPWV). At Southern Cross Bill has led investments and is a Board Member or Observer in Mocana, Bislr, Mantara, Liaise, and Shoes of Prey. Before co-founding Southern Cross, Bill was the start-up CEO of Mantara, a company that makes high performance, content-based message routing systems. Prior to moving to Australia, Bill had 12 years of research, operational, and entrepreneurial experience in the United States. Bill earned a Bachelor of Science, MBA and Juris Doctorate degree (University of Richmond).

## Investment focus

### Industry

| Industry | Investments | Share |
| --- | --- | --- |
| Software | 6 | 22% |
| SaaS | 5 | 19% |
| Analytics | 5 | 19% |
| Artificial Intelligence | 4 | 15% |
| Machine Learning | 3 | 11% |

42 industries tracked in total.

### Stage

| Stage | Investments | Share |
| --- | --- | --- |
| Series A | 7 | 26% |
| Seed | 5 | 19% |
| Series B | 5 | 19% |
| Funding Round | 3 | 11% |
| Venture - Series Unknown | 2 | 7% |

6 stages tracked in total.

### Country

| Country | Investments | Share |
| --- | --- | --- |
| Australia | 11 | 41% |
| United States | 4 | 15% |

## Investments

| Company | Description | Amount | Stage | Date | Website |
| --- | --- | --- | --- | --- | --- |
| Diraq | Diraq uses spins in silicon quantum dots as qubits. Diraq's qubits are compatible with existing CMOS processes and can fit billions of qubits on a single chip. To transform our world, quantum computers need billions of qubits and Diraq has the IP, the team and the plan to get there. | $15M | Series A | Jul 08, 2025 |  |
| QuintessenceLabs | QuintessenceLabs has developed a suite of data security technology, products, and solutions to secure valuable digital information in-transit, at-rest or in-use. By centralizing the management and control of data-security policy and harnessing quantum science properties to strengthen data security solutions, its solutions maximize security,increase ROI from existing assets, and reduce data-security complexities.Customers include financial services companies such as Westpac Group, a leading Australian bank, Technology providers, such as NetDocuments, a cloud storage provider for the legal industry, and PKWare, federal customers such as the US State Department, and defence primes such as Boeing Corporation and Northrop Grumman. | $12.7M | Venture - Series Unknown | Apr 03, 2025 |  |
| Quantum Brilliance | Quantum Brilliance builds room temperature quantum computers powered by synthetic diamond, enabling applications in everyday computing, including edge and massively parrellelized computing. | $20M | Series A | Jan 15, 2025 |  |
| Diraq | Diraq uses spins in silicon quantum dots as qubits. Diraq's qubits are compatible with existing CMOS processes and can fit billions of qubits on a single chip. To transform our world, quantum computers need billions of qubits and Diraq has the IP, the team and the plan to get there. | $7M | Series A | Jun 24, 2024 |  |
| Sundrive Solar | Sundrive Solar is a solar technology start-up. SunDrive is creating unique solutions to reduce the cost of high-efficiency solar cells, whilst enhancing their performance and sustainability by utilizing more abundant materials. | $13.2M | Series A | Oct 12, 2022 |  |
| QuintessenceLabs | QuintessenceLabs has developed a suite of data security technology, products, and solutions to secure valuable digital information in-transit, at-rest or in-use. By centralizing the management and control of data-security policy and harnessing quantum science properties to strengthen data security solutions, its solutions maximize security,increase ROI from existing assets, and reduce data-security complexities.Customers include financial services companies such as Westpac Group, a leading Australian bank, Technology providers, such as NetDocuments, a cloud storage provider for the legal industry, and PKWare, federal customers such as the US State Department, and defence primes such as Boeing Corporation and Northrop Grumman. | $18.8M | Series B | Oct 26, 2021 |  |
| Prospection | Prospection is a Pioneer in healthcare data analytics. Using predictive analytics and machine learning with real world healthcare data to unearth insights that help research, develop and target better healthcare outcomes for patients. Founded out of Sydney’s Cicada Innovations in 2012, Prospection works with government, pharmaceutical companies andthe medical community across more than 90 therapy programs, including immuno-oncology, Diabetes, Respiratory, HIV and hepatitis, in Australia, Japan, Asia Pacific, UK and USA. | $33.1M | Series B | Sep 13, 2021 |  |
| Quantum Brilliance | Quantum Brilliance builds room temperature quantum computers powered by synthetic diamond, enabling applications in everyday computing, including edge and massively parrellelized computing. | $9.7M | Seed | Aug 26, 2021 |  |
| Kapiche | Kapiche is a B2B SaaS company that has built an experience intelligence platform to help customer-centric organisations understand and optimize the experiences they deliver. The platform is built around their Natural Language Processing technology which can take 10s of 1,000s of pieces of unseen customer/employee feedback data (both structuredand unstructured) and, in minutes, with no prior setup and no pre-trained models, identify the salient themes being discussed, how the respondents feel about those themes, and what impact it has on your business. | $1.5M | Seed | Apr 30, 2021 |  |
| Pending AI | Artificial intelligence- and quantum mechanics-based capabilities to Design, Make, Test, and Analyse novel pharmaceuticals. |  | Venture - Series Unknown | Jan 01, 2021 |  |

10 of 27 investments shown.

## Co-investors
- [Felicis](https://shizune.co/investors/profile/felicis-ventures) — VC Fund, 3 deals together
- [Index Ventures](https://shizune.co/investors/profile/index-ventures) — VC Fund, 3 deals together
- [InterValley Ventures](https://shizune.co/investors/profile/intervalley-ventures-pty-ltd) — VC Fund, 3 deals together
- [Uniseed](https://shizune.co/investors/profile/uniseed-vc) — VC Fund, 3 deals together
- [Blackbird Ventures](https://shizune.co/investors/profile/blackbird-ventures-australia) — VC Fund, 2 deals together
- [CP Ventures](https://shizune.co/investors/profile/cp-ventures) — VC Fund, 2 deals together

## About Main Sequence Ventures

VC Fund · Sydney, Australia

Main Sequence Ventures invests in ambitious founders creating the next set of global industries leveraging deep tech or frontier technologies. The firm is backed by the Australian National Science Agency, CSIRO, the Australian Federal Government, and private investors. All Main Sequence investments leverage world-leading research from Australianpublic research organizations such as CSIRO, any of Australia's 41 universities or its multitude of other industry research agencies.

5 contacts available at Main Sequence Ventures.

| Name | Title | Profile |
| --- | --- | --- |
| Mike Zimmerman | Partner | https://shizune.co/investors/profile/michael-zimmerman |
| Phil Morle | Partner | https://shizune.co/investors/profile/phil-morle |
| Alezeia Brown | Investment Manager | https://shizune.co/investors/profile/alezeia-brown-417a |
| Bill Bartee | Partner | https://shizune.co/investors/profile/bill-bartee |
| Jun Qu | Deep tech VC | https://shizune.co/investors/profile/jun-qu-3efc |

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- [General Catalyst](https://shizune.co/investors/profile/general-catalyst-partners) — VC Fund

## FAQ

### What does Bill Bartee invest in?

Bill Bartee invests primarily in Software, SaaS and Analytics startups, most often at Series A and Seed stage. Most of the 27 investments tracked by Shizune back companies in Australia. The Investment Focus section breaks down every industry, stage and country in the portfolio.

### When did Bill Bartee last invest?

The most recent investment recorded for Bill Bartee closed in Jul 2025. Shizune tracks 27 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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