# Build on Bitcoin funding: rounds and investors

> Build on Bitcoin has raised $14M across 2 rounds since 2025. Investors include Amber Group, Castle Island Ventures and RockawayX. Every round with its source.

Source: https://millionrounds.com/company/build-on-bitcoin (Millionrounds; every figure on the page links to its filing or article)

Cayman Islands · [Venture startup](https://millionrounds.com/companies)

# Who invested in *Build on Bitcoin*

2 rounds we have observed, with the 4 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.

Web3 & Crypto

Raised 12 months ago

Funding summary Updated 26 Oct 2026

**$14M** raised across 2 rounds since 2025, from 2 sources

**$9.5M** Venture **$4.2M** Venture

- **Latest round:** Venture, $4.2M Nov 2025
- **Biggest round:** $9.5M Venture · Aug 2025
- **Investors:** 4

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.

2026

**$9.5M** Venture

**$4.2M** Venture

- **First round:** Venture, $9.5M
- **Biggest round:** $9.5M
- **Between rounds:** 3 months

## The rounds

- **Nov 2025** Venture **$4.2M** *1 new* *3 returning* [Coinbase Ventures](https://millionrounds.com/fund/coinbase) [Amber Group](https://millionrounds.com/fund/amber-group) [Castle Island Ventures](https://millionrounds.com/fund/castle-island-ventures) [RockawayX](https://millionrounds.com/fund/rockawayx) Source recorded
- **Aug 2025** Venture **$9.5M** *3 new* [Amber Group](https://millionrounds.com/fund/amber-group) [Castle Island Ventures](https://millionrounds.com/fund/castle-island-ventures) [RockawayX](https://millionrounds.com/fund/rockawayx) Source recorded

## 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.

**Venture** 2025 **Venture** 2025 [Amber Group](https://millionrounds.com/fund/amber-group) [Castle Island Ventures](https://millionrounds.com/fund/castle-island-ventures) [RockawayX](https://millionrounds.com/fund/rockawayx) [Coinbase Ventures](https://millionrounds.com/fund/coinbase)

## Everyone who backed them

[Amber Group](https://millionrounds.com/fund/amber-group) VC firm **2** rounds

[Castle Island Ventures](https://millionrounds.com/fund/castle-island-ventures) VC firm **2** rounds

[RockawayX](https://millionrounds.com/fund/rockawayx) VC firm **2** rounds

[Coinbase Ventures](https://millionrounds.com/fund/coinbase) Corporate VC **1** round

Missing a round, or an investor who was in one? [Tell us](https://millionrounds.com/corrections?slug=build-on-bitcoin).

## Quick answers about Build on Bitcoin

### Who invested in Build on Bitcoin?

Build on Bitcoin's investors include Amber Group, Castle Island Ventures, RockawayX and Coinbase Ventures.

### How much has Build on Bitcoin raised?

Build on Bitcoin has raised $14M across 2 rounds since 2025.

### When did Build on Bitcoin last raise?

Build on Bitcoin's most recent round was a Venture of $4.2M in Nov 2025.

### What was Build on Bitcoin's biggest round?

Build on Bitcoin's largest round on record is $9.5M (Venture), in Aug 2025.

### Who backed Build on Bitcoin first?

Build on Bitcoin's first round on record, in Aug 2025, was backed by Amber Group, Castle Island Ventures and RockawayX.

### What stage is Build on Bitcoin at?

Build on Bitcoin's latest named round is a Venture, in Nov 2025.

### Where is Build on Bitcoin based?

Build on Bitcoin is based in Cayman Islands.

## Companies like Build on Bitcoin

In the same sector, and raised in the last eighteen months.

[**Tempus** $1.0B · Sept 2026](https://millionrounds.com/company/tempus)[**LurraPay** $7.0M · Jul 2026](https://millionrounds.com/company/lurrapay)[**TITAN** $111M · Jun 2026](https://millionrounds.com/company/titan)[**Variational** $52M · May 2026](https://millionrounds.com/company/variational)[**Wildcat Labs** $3.5M · Sept 2025](https://millionrounds.com/company/wildcat-labs)[**OneBalance** $20M · Jun 2025](https://millionrounds.com/company/onebalance)

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