Sie Ventures

Sie runs open-application accelerator cohorts — Sie Foundations for pre-raise preparation and Sie Catalyst for companies actively fundraising — followed by a selection process that emphasizes diverse founding teams across fintech, digital health, AI, deeptech, sustainability and femtech. The firm has run at least five Catalyst cohorts and reports that more than half of one recent cohort closed funding rounds during the program itself (per firm website). Selected companies then gain exposure to Sie's syndicate of 215 angel and family-office investors.

Founding partner Triin Linamagi leads the platform. Sie operates without a traditional general-partner committee structure; investment decisions flow through the syndicate, with Sie selecting cohort companies and then offering its investor community the opportunity to commit capital via special purpose vehicles.

Sie operates as a hybrid — it is both an accelerator (running Sie Foundations and Sie Catalyst programs) and an active angel syndicate. The firm was named UKBAA Angel Group of the Year in 2024 and Accelerator of the Year in 2025. In 2025 it also launched the Arāya Sie Fund, a dedicated pooled vehicle with a £7.5m first close, adding a fund structure to the existing syndicate model (per firm website, 2025).

Sie invests directly into pre-seed and seed-stage operating companies, typically as a syndicate participant alongside institutional lead investors such as Balderton Capital, Seedcamp, Female Founders Fund and Eka Ventures. The firm does not publicly disclose making fund commitments to other GPs.

Sie concentrates on pre-seed and seed rounds. Companies it backs have included Fifth Dimension AI (£2.3m seed, led by Seedcamp), Cino (€3.5m seed, led by Balderton Capital) and FitCollective (£3m pre-seed), all per the firm's own published material.

Yes. In 2025, Triin Linamagi partnered with Arāya Ventures founder Rupa Popat to launch the Arāya Sie Fund, which announced a £7.5m first close to back female founders in AI, deeptech, fintech, healthcare and sustainability (per firm website, 2025). That fund operates alongside the existing Sie syndicate and accelerator programs.

Sie actively co-invests. Its syndicate has participated in rounds led or joined by Lunar Ventures, Balderton Capital, Seedcamp, Connect Ventures, Tera Ventures, APX, Faber, SuperSeed, Eka Ventures, Bayer and others. The firm's model is built on pairing cohort graduates with institutional investors and then offering its angel network the opportunity to invest alongside them.