# Quantum SI funding: rounds and investors

> Quantum SI has raised $50M across 1 round since 2025. Investors include Redmile Group, Foresite Capital and Eldridge. Every round with its source.

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

United States · [Funded startup](https://millionrounds.com/companies)

# Who invested in *Quantum SI*

One round we have observed, with the 3 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.

Biotech

Funding summary Updated 26 Oct 2026

**$50M** raised across 1 round since 2025, from 1 source

- **Latest round:** Round, $50M Jul 2025
- **Investors:** 3

See who backed them

## The rounds

- **Jul 2025** Round **$50M** [Redmile Group](https://millionrounds.com/fund/redmile-group) [Foresite Capital](https://millionrounds.com/fund/forsite-capital) [Eldridge](https://millionrounds.com/fund/eldridge) Source recorded

## Founders and team

From Quantum SI's own website: 3 on the team.

- **Jeff Hawkins** President and Chief Executive Officer
- **Jeff Keyes** Chief Financial Officer
- **Lindsay Thompson** Chief Human Resources Officer

## Everyone who backed them

[Redmile Group](https://millionrounds.com/fund/redmile-group) VC firm **1** round

[Foresite Capital](https://millionrounds.com/fund/forsite-capital) Private equity **1** round

[Eldridge](https://millionrounds.com/fund/eldridge) Private equity **1** round

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

## Also claim to have backed them

This firm lists Quantum SI as a portfolio company on their own website, but no report of a round names it. They are the firms' own claims, kept apart from the rounds above.

[HighCape Partners](https://millionrounds.com/fund/highcape-capital) VC firm Per its own site

## Quick answers about Quantum SI

### Who invested in Quantum SI?

Quantum SI's investors include Redmile Group, Foresite Capital and Eldridge.

### How much has Quantum SI raised?

Quantum SI has raised $50M across 1 round since 2025.

### When did Quantum SI last raise?

Quantum SI's most recent round was an Undisclosed round of $50M in Jul 2025.

### What was Quantum SI's biggest round?

Its most recent round, $50M in Jul 2025, is also its largest on record.

### Who backed Quantum SI first?

Quantum SI's first round on record, in Jul 2025, was backed by Redmile Group, Foresite Capital and Eldridge.

### What stage is Quantum SI at?

Quantum SI's latest named round is an Undisclosed round, in Jul 2025.

### Where is Quantum SI based?

Quantum SI is based in the United States.

## Companies like Quantum SI

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

[**Star Therapeutics** $325M · Oct 2026](https://millionrounds.com/company/star-therapeutics)[**Promaxo** $106M · Oct 2026](https://millionrounds.com/company/promaxo)[**Prolific Machines** $105M · Oct 2026](https://millionrounds.com/company/prolific-machines)[**IMIO** $19M · Oct 2026](https://millionrounds.com/company/imio)[**Clinical Ink** $24M · Oct 2026](https://millionrounds.com/company/clinical-ink)[**Rejuvenate Bio** $13M · Oct 2026](https://millionrounds.com/company/rejuvenate-bio)

## Find investors like these

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