United States · 
Who invested in Theseus?
Theseus's investors include First Round Capital, Y Combinator, Pioneer Fund and Lux Capital. First Round Capital led its latest round.
United States · Seed startup
Who invested in Theseus
One round we have observed, with the 4 investors named in it. Every figure came from a named source, and where the company reported a raise to the SEC itself, that is shown beside it.
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Funding summaryUpdated 15 Nov 2026
$4.3Mraised across 1 round since 2025, from 1 source
- Latest round
- Seed, $4.3MApr 2025
- Led by
- First Round Capital
- Investors
- 4 (1 led)
The rounds
- Apr 2025
Founders and team
From Theseus's own website: 2 on the team.
- Ian LaffeyChief Executive Officer
- Sacha LévyChief Technology Officer
Everyone who backed them
Missing a round, or an investor who was in one? Tell us.
Quick answers about Theseus
How much has Theseus raised?
Theseus has raised $4.3M across 1 round since 2025.
When did Theseus last raise?
Theseus's most recent round was a Seed of $4.3M in Apr 2025, led by First Round Capital.
What was Theseus's biggest round?
Its most recent round, $4.3M in Apr 2025, is also its largest on record.
Who backed Theseus first?
Theseus's first round on record, in Apr 2025, was backed by First Round Capital, Y Combinator and Pioneer Fund and 1 others.
What stage is Theseus at?
Theseus's latest named round is a Seed, in Apr 2025.
Where is Theseus based?
Theseus is based in the United States.
Who led Theseus's rounds?
First Round Capital led the Seed in 2025.
Companies like Theseus
In the same sector, and raised in the last eighteen months.
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