United States · 
Who invested in Ostium?
Ostium's investors include General Catalyst, LocalGlobe, Soma Capital, SE Ventures and Susquehanna International Group (SIG), and 3 more on record. General Catalyst led its latest round.
20242025
$3.5MSeed$20MSeries A
United States · Series A startup
Who invested in Ostium
2 rounds we have observed, with the 8 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.
Raised 11 months ago
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Funding summaryUpdated 5 Nov 2026
$24Mraised across 2 rounds since 2023, from 2 sources
$3.5MSeed$20MSeries A
- Latest round
- Series A, $20MDec 2025
- Led by
- General Catalyst
- Step-upi
- 5.7×
- Investors
- 8 (1 led)
The funding story
Each circle is a round, placed by date and sized by amount. The line above is the running total.
- First round
- Seed, $3.5M Oct 2023
- Biggest round
- $20M Series A · Dec 2025
- Between rounds
- 2.2 years from the last two
The rounds
- Dec 2025Series A$20M5 new2 returning
Reported by Ventureburn
- Oct 2023
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.
Everyone who backed them
Jump's crypto armVC firm1round
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Also claim to have backed them
These 2 firms list Ostium as a portfolio company on their own websites, but no report of a round names them. They are the firms' own claims, kept apart from the rounds above.
Quick answers about Ostium
How much has Ostium raised?
Ostium has raised $24M across 2 rounds since 2023.
When did Ostium last raise?
Ostium's most recent round was a Series A of $20M in Dec 2025, led by General Catalyst.
What was Ostium's biggest round?
Its most recent round, $20M in Dec 2025, is also its largest on record.
Who backed Ostium first?
Ostium's first round on record, in Oct 2023, was backed by General Catalyst, LocalGlobe and Susquehanna International Group (SIG).
What stage is Ostium at?
Ostium's latest named round is a Series A, in Dec 2025.
Where is Ostium based?
Ostium is based in the United States.
Who led Ostium's rounds?
General Catalyst led the Series A in 2025.
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In the same sector, and raised in the last eighteen months.
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