# Castle funding: rounds and investors

> Castle has raised $1.0M across 1 round since 2025. Investors include Boost VC and Winklevoss Capital. Every round with its source.

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

United States · [Pre-seed startup](https://millionrounds.com/companies)

# Who invested in *Castle*

One round we have observed, with the 2 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.

Cybersecurity Web3 & Crypto

Y Combinator: W16

Funding summary Updated 26 Oct 2026

**$1.0M** raised across 1 round since 2025, from 1 source

- **Latest round:** Pre-seed, $1.0M Jun 2025
- **Investors:** 2

See who backed them

[**Castle** Real estate 1 / 14 Their pitch deck **Castle's pitch deck, 14 slides** Each slide read for what it argues, against the decks that raised at the same stage.](https://millionrounds.com/decks/castle)

## The rounds

- **Jun 2025** Pre-seed **$1.0M** [Boost VC](https://millionrounds.com/fund/boost-vc) [Winklevoss Capital](https://millionrounds.com/fund/winklevoss-capital) Source recorded

## Founders and team

From Castle's own website: 1 founder, 1 on the team.

**John Domsy** Founder of Cardata

- **Scott Burns** CTO of SeQent

## Everyone who backed them

[Boost VC](https://millionrounds.com/fund/boost-vc) VC firm **1** round

[Winklevoss Capital](https://millionrounds.com/fund/winklevoss-capital) Family office **1** round

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

## Also claim to have backed them

These 6 firms list Castle 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.

[UpHonest Capital](https://millionrounds.com/fund/uphonest-capital) VC firm Per its own site

[Red Swan Ventures](https://millionrounds.com/fund/red-swan-ventures) VC firm Per its own site

[Walking](https://millionrounds.com/fund/walking) VC firm Per its own site

[SparkLabs Group](https://millionrounds.com/fund/sparklabs-group) VC firm Per its own site

[MDSV Capital](https://millionrounds.com/fund/mdsv-capital) VC firm Per its own site

[Spruce Grove Capital](https://millionrounds.com/fund/spruce-grove-capital) Investment firm Per its own site

## Quick answers about Castle

### Who invested in Castle?

Castle's investors include Boost VC and Winklevoss Capital.

### How much has Castle raised?

Castle has raised $1.0M across 1 round since 2025.

### When did Castle last raise?

Castle's most recent round was a Pre-seed of $1.0M in Jun 2025.

### What was Castle's biggest round?

Its most recent round, $1.0M in Jun 2025, is also its largest on record.

### Who backed Castle first?

Castle's first round on record, in Jun 2025, was backed by Boost VC and Winklevoss Capital.

### What stage is Castle at?

Castle's latest named round is a Pre-seed, in Jun 2025.

### Where is Castle based?

Castle is based in the United States.

## Companies like Castle

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

[**Kalshi** $2.7B · Oct 2026](https://millionrounds.com/company/kalshi)[**STRIVE** $1.3B · Oct 2026](https://millionrounds.com/company/strive)[**FORT Robotics** $39M · Oct 2026](https://millionrounds.com/company/fort-robotics)[**Arda** $233M · Oct 2026](https://millionrounds.com/company/arda)[**Binance.US** $300M · Oct 2026](https://millionrounds.com/company/binance-us)[**Fission** $10M · Oct 2026](https://millionrounds.com/company/fission)

## 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