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into formidable founders^[1]

[1]“A formidable person is one who seems like they’ll get what they want, regardless of whatever obstacles are in the way.”— Paul Graham

[1]“A formidable person is one who seems like they’ll get what they want, regardless of whatever obstacles are in the way.”

Sam was part of YC's inaugural batch in S05 and founded OpenAI as YC Research in 2015.

During YC

Brian, Joe, and Nate did YC in W09.

During YC

The Collison brothers did YC twice—first in W07 and then in S09, when they started Stripe.

During YC

Fred and Brian met on Reddit and did YC in S12.

During YC

Andy, Stanley, Tony, and Evan did YC in S13.

During YC

Alexandr and Lucy did YC S16 and pivoted during the batch.

During YC

Arash and Drew started Dropbox at MIT and did YC in S07.

During YC

Alexis and Steve were in the inaugural YC batch in S05.

During YC

Apoorva, Max, and Brandon did YC in S12.

During YC

Sid and Dmytro did YC in S14.

During YC

Tarek and Luana did YC in W19.

During YC

Haya and Amjad interviewing for the YC W18 batch.

During YC

Michael, Justin, Kyle, and Emmett in YC W07.

OpenAI

Airbnb

Stripe

Coinbase

DoorDash

Scale AI

Dropbox

Reddit

Instacart

GitLab

Kalshi

Replit

Twitch

$1.3 Trillionin combined valuation

All companies

Now

Sam built OpenAI into a $500B company.

Now

Airbnb went public in 2020 at an over $100B valuation.

Now

Stripe is now the internet’s $107B payments backbone.

Now

Coinbase went public in 2021 at a $86B valuation.

Now

DoorDash went public in 2020 at a valuation of $39B.

Now

In 2025, Meta acquired 49% of Scale for over $14B.

Now

Dropbox had the biggest tech IPO of 2018 at a $9B valuation.

Now

Reddit went public in 2024 at a $6.4B valuation.

Now

Instacart went public in 2023 at a $10B valuation.

Now

GitLab went public in 2021 at an $11B valuation.

Now

Kalshi reached an $11B valuation in 2025.

Now

Replit became a leading AI coding platform valued at over $9B.

Now

Twitch was acquired by Amazon for nearly $1B.

In 2005, Y Combinator developed a new model of startup funding. Four times a year we invest $500k in a select group of startups. They move to San Francisco for three months, where we work intensively with them to get the company into the best possible shape, before they present to a large audience of investors on Demo Day.

But YC doesn’t end on Demo Day. We and the YC alumni network continue to help founders for the life of their company, and beyond.

In Founders’ Words

YC compresses months of growth into weeks.

[Aman Mishra]The sense of urgency is so infectious among founders that it becomes the most productive period in most people’s lives.

[Adith Reddi]

It’s a community of founders that you can’t find anywhere else.

[Bishesh Khadka]It feels like having the entire world at your back—from Partners to batchmates.

[Justin Lee]

Being surrounded by the top 1% of founders in the world just completely resets the bar.

[Fern Morrison]You leave with a completely new sense of how fast ‘fast’ can be.

[Aman Mishra]

Be in the room with …

“This is the greatest time ever to start a company. YC is where some of the world’s most ambitious builders come to learn fast, take on hard problems, and get going.”