# Sieve funding: rounds and investors

> Sieve has raised $4.0M across 2 rounds since 2022. Investors include Y Combinator and Clocktower Ventures. Every round with its source.

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

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

# Who invested in *Sieve*

2 rounds we have observed, with the 2 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.

AI

Raised 10 months ago Y Combinator: W22

Funding summary Updated 26 Oct 2026

**$4.0M** raised across 2 rounds since 2022, from 2 sources

- **Latest round:** Venture Jan 2026
- **Biggest round:** $4.0M Seed · Nov 2022
- **Investors:** 2

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.

2023 2024 2025 2026

**$4.0M** Seed

**?** Venture

- **First round:** Seed, $4.0M
- **Biggest round:** $4.0M
- **Between rounds:** 3.2 years

## The rounds

- **Jan 2026** Venture **Amount undisclosed** *1 new* *1 returning* [Y Combinator](https://millionrounds.com/fund/y-combinator) [Clocktower Ventures](https://millionrounds.com/fund/clocktower-ventures) Source recorded
- **Nov 2022** Seed **$4.0M** *1 new* [Y Combinator](https://millionrounds.com/fund/y-combinator) 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.

**Seed** 2022 **Venture** 2026 [Y Combinator](https://millionrounds.com/fund/y-combinator) [Clocktower Ventures](https://millionrounds.com/fund/clocktower-ventures)

## Everyone who backed them

[Y Combinator](https://millionrounds.com/fund/y-combinator) Accelerator **2** rounds

[Clocktower Ventures](https://millionrounds.com/fund/clocktower-ventures) VC firm **1** round

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

## Quick answers about Sieve

### Who invested in Sieve?

Sieve's investors include Y Combinator and Clocktower Ventures.

### How much has Sieve raised?

Sieve has raised $4.0M across 2 rounds since 2022. One round did not disclose an amount, so the total is a floor.

### When did Sieve last raise?

Sieve's most recent round was a Venture in Jan 2026.

### What was Sieve's biggest round?

Sieve's largest round on record is $4.0M (Seed), in Nov 2022.

### Who backed Sieve first?

Sieve's first round on record, in Nov 2022, was backed by Y Combinator.

### What stage is Sieve at?

Sieve's latest named round is a Venture, in Jan 2026.

### Where is Sieve based?

Sieve is based in the United States.

## Companies like Sieve

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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