# RIOS funding: rounds and investors

> RIOS has raised $13M across 1 round since 2024. Investors include Alumni Ventures and Main Sequence Ventures. Every round with its source.

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

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

# Who invested in *RIOS*

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.

AI

Funding summary Updated 26 Oct 2026

**$13M** raised across 1 round since 2024, from 1 source

- **Latest round:** Series B, $13M Mar 2024
- **Investors:** 2

See who backed them

## The rounds

- **Mar 2024** Series B **$13M** [Alumni Ventures](https://millionrounds.com/fund/us-strategic-tech-fund-an-alumni-ventures-fund) [Main Sequence Ventures](https://millionrounds.com/fund/main-sequence) Source recorded

## Everyone who backed them

[Alumni Ventures](https://millionrounds.com/fund/us-strategic-tech-fund-an-alumni-ventures-fund) VC firm **1** round

[Main Sequence Ventures](https://millionrounds.com/fund/main-sequence) VC firm **1** round

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

## Also claim to have backed them

These 2 firms list RIOS 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.

[Grit Ventures](https://millionrounds.com/fund/grit-ventures) VC firm Per its own site

[Channel Angels](https://millionrounds.com/fund/channel-angels) Angel network Per its own site

## Quick answers about RIOS

### Who invested in RIOS?

RIOS's investors include Alumni Ventures and Main Sequence Ventures.

### How much has RIOS raised?

RIOS has raised $13M across 1 round since 2024.

### When did RIOS last raise?

RIOS's most recent round was a Series B of $13M in Mar 2024.

### What was RIOS's biggest round?

Its most recent round, $13M in Mar 2024, is also its largest on record.

### Who backed RIOS first?

RIOS's first round on record, in Mar 2024, was backed by Alumni Ventures and Main Sequence Ventures.

### What stage is RIOS at?

RIOS's latest named round is a Series B, in Mar 2024.

### Where is RIOS based?

RIOS is based in the United States.

## Companies like RIOS

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

[**SpaceX** $42B · Oct 2026](https://millionrounds.com/company/spacex)[**xPay** $1.5M · Oct 2026](https://millionrounds.com/company/xpay)[**Albert Invent** $20M · Oct 2026](https://millionrounds.com/company/albert-invent)[**FORT Robotics** $39M · Oct 2026](https://millionrounds.com/company/fort-robotics)[**Pika** $216M · Oct 2026](https://millionrounds.com/company/pika)[**Vertical Semiconductor** $84M · Oct 2026](https://millionrounds.com/company/vertical-semiconductor)

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