# Thomas Stewart

> Thomas Stewart is the New York-based co-founder and CEO of Hadrius, an AI-native compliance platform for regulated financial firms. A University of Virginia graduate trained in mathematics, economics, and physics, he moved through software engineering and two earlier startups before turning the firsthand compliance burden of running an SEC-registered investment adviser into Hadrius. The Y Combinator company announced a $22 million Series A in July 2026, bringing combined seed and Series A funding to $27 million, and says more than 500 firms use its platform.

- **Role:** Co-founder and CEO at Hadrius
- **Organizations:** Hadrius, Quantbase, Bazza, Abeyon, CoStar Group, University of Virginia, Y Combinator
- **Education:** Bachelor's degrees in Mathematics and Economics; minor in Physics, University of Virginia, Algorithms I & II coursework, Princeton University, Winter 2023 batch, Y Combinator
- **Known for:** Co-founded and leads Hadrius, a Y Combinator Winter 2023 company., Built Hadrius from firsthand experience operating the compliance program of an SEC-registered investment adviser., Announced a $22 million Series A in July 2026 led by CRV, with combined seed and Series A funding of $27 million.

## Career timeline

- **2016-2019** — Worked as a physics researcher at the University of Virginia's High Energy Physics Laboratory and participated in the Putnam Math Team.
- **2018-2019** — Co-founded Bazza, which was later acquired by Copiri.
- **2020** — Worked as an AI engineer at Abeyon; public professional profiles also list software engineering work at CoStar Group.
- **2021-2023** — Founded and led Quantbase, an SEC-registered investment adviser that was acquired.
- **2023** — Co-founded Hadrius with Allen Calderwood and Som Mohapatra; the company joined Y Combinator's Winter 2023 batch and raised a $2 million seed round.
- **2024** — Reported that Hadrius managed compliance for more than $100 billion in assets across more than 60 clients after its first year.
- **2026** — Hadrius announced a $22 million Series A led by CRV, bringing combined seed and Series A funding to $27 million, and reported use by more than 500 firms.

## Achievements

- Co-founded and leads Hadrius, a Y Combinator Winter 2023 company.
- Built Hadrius from firsthand experience operating the compliance program of an SEC-registered investment adviser.
- Announced a $22 million Series A in July 2026 led by CRV, with combined seed and Series A funding of $27 million.
- Expanded Hadrius to more than 500 financial institutions and investment firms, according to the company.
- Previously founded Quantbase, which was acquired, and co-founded Bazza, which was also acquired.
- Earned the FINRA Series 65 qualification.

## Latest updates

- **2026-08** — Hadrius published a recap of its discussion on compliance officers becoming owners of firm integrity after busywork is automated.
- **2026-07** — Hadrius announced integration with the Claude Compliance API for archiving Claude Enterprise conversations and activity.
- **2026-07** — Hadrius announced a $22 million Series A led by CRV and said more than 500 firms were running compliance programs on the platform.
- **2026-02** — Stewart spoke publicly about governing AI adoption in financial services and the shift from industry resistance to implementation.

## Links

- Website: https://www.hadrius.com
- LinkedIn: https://www.linkedin.com/in/thomasjstewart

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Profile page: https://yespress.io/thomas-stewart
Published by YesPress — https://yespress.io
Last updated: 2026-08-27