# Promethium funding: rounds and investors > Promethium has raised $29M across 2 rounds since 2018. Investors include Zetta Venture Partners, Insight Partners and 406 Ventures. Every round with its source. Source: https://millionrounds.com/company/promethium (Millionrounds; every figure on the page links to its filing or article) United States · [Series A startup](https://millionrounds.com/companies) # Who invested in *Promethium* 2 rounds we have observed, with the 3 investors named in them. Every figure came from a named source, and where the company reported a raise to the SEC itself, that is shown beside it. Big Data & Analytics Cleantech Funding summary Updated 26 Oct 2026 **$29M** raised across 2 rounds since 2018, from 2 sources **$2.5M** Seed **$26M** Series A - **Latest round:** Series A, $26M Feb 2022 - **Step-up i:** 10.4× - **Investors:** 3 See who backed them ## The funding story Each circle is a round, placed by date and sized by amount. The line above is the running total. 2019 2020 2021 2022 **$2.5M** Seed **$26M** Series A - **First round:** Seed, $2.5M - **Biggest round:** $26M - **Between rounds:** 3.3 years [**Promethium** Cleantech 1 / 15 Their pitch deck **Promethium's pitch deck, 15 slides** Each slide read for what it argues, against the decks that raised at the same stage.](https://millionrounds.com/decks/promethium) ## The rounds - **Feb 2022** Series A **$26M** *2 new* *1 returning* [Insight Partners](https://millionrounds.com/fund/insight-venture-partners) [406 Ventures](https://millionrounds.com/fund/406-ventures) [Zetta Venture Partners](https://millionrounds.com/fund/zetta-venture-partners) Source recorded - **Oct 2018** Seed **$2.5M** *1 new* [Zetta Venture Partners](https://millionrounds.com/fund/zetta-venture-partners) Reported by FinSMEs ## Who was in which round The busiest backers across the latest rounds. A filled square is a round they joined; a dark one, a round they led. **Seed** 2018 **Series A** 2022 [Zetta Venture Partners](https://millionrounds.com/fund/zetta-venture-partners) [Insight Partners](https://millionrounds.com/fund/insight-venture-partners) [406 Ventures](https://millionrounds.com/fund/406-ventures) ## Everyone who backed them [Zetta Venture Partners](https://millionrounds.com/fund/zetta-venture-partners) VC firm **2** rounds [Insight Partners](https://millionrounds.com/fund/insight-venture-partners) VC firm **1** round [406 Ventures](https://millionrounds.com/fund/406-ventures) VC firm **1** round Missing a round, or an investor who was in one? [Tell us](https://millionrounds.com/corrections?slug=promethium). ## Quick answers about Promethium ### Who invested in Promethium? Promethium's investors include Zetta Venture Partners, Insight Partners and 406 Ventures. ### How much has Promethium raised? Promethium has raised $29M across 2 rounds since 2018. ### When did Promethium last raise? Promethium's most recent round was a Series A of $26M in Feb 2022. ### What was Promethium's biggest round? Its most recent round, $26M in Feb 2022, is also its largest on record. ### Who backed Promethium first? Promethium's first round on record, in Oct 2018, was backed by Zetta Venture Partners. ### What stage is Promethium at? Promethium's latest named round is a Series A, in Feb 2022. ### Where is Promethium based? Promethium is based in the United States. ## Companies like Promethium In the same sector, and raised in the last eighteen months. [**Amogy** $125M · Oct 2026](https://millionrounds.com/company/amogy)[**SpaceX** $42B · Oct 2026](https://millionrounds.com/company/spacex)[**LanzaJet** $67M · Oct 2026](https://millionrounds.com/company/lanzajet)[**STRIVE** $1.3B · Oct 2026](https://millionrounds.com/company/strive)[**Pivot Energy** $500M · Oct 2026](https://millionrounds.com/company/pivot-energy)[**Xona** $512M · Oct 2026](https://millionrounds.com/company/xona) ## Find investors like these Search every investor by what they have actually funded, then narrow to your stage and market. Free. Open the investor searchOr these rounds in the app