Startups · Company Building
One accelerator, four thousand-plus companies, and a top ten that alone accounts for roughly two-thirds of everything YC has ever returned. Here's the actual list, with the numbers behind each name.
Every startup accelerator claims a few big wins. Y Combinator is the one where the claim actually holds up under scrutiny. Since Paul Graham, Jessica Livingston, Robert Morris, and Trevor Blackwell started the program in a Cambridge apartment in 2005, YC has funded more than 4,000 companies. Ninety-plus of them became unicorns. And a genuinely small cluster at the very top — maybe ten names — has generated something like two-thirds of all the value the entire program has ever produced. We went through the funding data, the public filings, and the exit history to figure out which ten those actually are, and why the gap between them and everyone else is as large as it is.
Ranked by what they're actually worth
| Rank | Company | YC Batch | Status & value |
|---|---|---|---|
| 1 | Stripe | S09 | Private, $159B valuation (Feb 2026) |
| 2 | Airbnb | W09 | Public (ABNB), $86.5B at IPO |
| 3 | DoorDash | S13 | Public (DASH), ~$95B market cap |
| 4 | Coinbase | S12 | Public (COIN), largest US crypto exchange |
| 5 | Instacart | S12 | Public (CART), 2023 IPO |
| 6 | S05 | Public (RDDT), 2024 IPO | |
| 7 | Dropbox | S07 | Public (DBX), one of YC's earliest breakouts |
| 8 | Twitch | W07 | Acquired by Amazon, ~$970M (2014) |
| 9 | Cruise | W14 | GM-backed, autonomous vehicles |
| 10 | Deel | W19 | Private unicorn, global payroll/HR |
Stripe alone, still private, is worth more than Airbnb's entire IPO valuation — a gap that says a lot about how payments infrastructure gets priced versus consumer marketplaces.
1. Stripe — the one that changed how the internet gets paid
Stripe is, by a wide margin, the most valuable company YC has ever backed, and it's not particularly close. Brothers Patrick and John Collison built it around a genuinely simple idea for 2010: let a developer accept payments with a few lines of code instead of weeks of banking paperwork. Fifteen years later, Stripe processed $1.9 trillion in payment volume in 2025 alone — something like 1.6% of global GDP moving through one company's infrastructure. A February 2026 tender offer valued it at $159 billion, still private, still one of the largest private companies on the planet.
2. Airbnb — three founders, an air mattress, and a category that didn't exist
Brian Chesky, Joe Gebbia, and Nathan Blecharczyk turned a rent-shortfall problem into an air mattress on their apartment floor, and then into the company that invented the modern short-term rental category outright. Airbnb went public in December 2020 at an $86.5 billion valuation and now operates in over 220 countries with more than eight million listings. It remains one of the two or three companies most often cited as proof that YC's earliest consumer bets weren't luck.
3. DoorDash — macarons to Stanford students, then a market
DoorDash started as PaloAltoDelivery.com, with Stanford students Tony Xu, Stanley Tang, Andy Fang, and Evan Moore literally delivering macarons to classmates to test whether local restaurants without delivery infrastructure would pay for it. They would. DoorDash's YC batch seed was $120,000; as of mid-August 2026, its public market cap sits somewhere in the $95 billion range, making it one of just four YC companies whose market value alone accounts for the overwhelming majority of everything the program has ever publicly returned.
4. Coinbase — crypto's most conventional company
There's something almost funny about the fact that the largest, most institutionally trusted crypto company in the U.S. came out of the same accelerator batch system as food-delivery apps and payroll software. Coinbase went public via direct listing in 2021 and has stayed the default on-ramp for both retail crypto buyers and, increasingly, institutional ones — proof that "boring and compliant" can still win in a category built on volatility.
5. Instacart — grocery delivery's quiet survivor
Instacart, technically Maplebear Inc. on the ticker, spent years as the perpetual "will it ever go public" story before finally listing in 2023. It's smaller today than the four names above it, but it's one of the four companies that together account for more than 84% of the total public market value YC has ever produced — a statistic that says as much about how top-heavy this list is as it does about any individual company.
6. Reddit — the front page of the internet was in YC's first batch
Here's a detail that surprises people who assume Reddit predates YC entirely: it was actually part of Y Combinator's very first batch, back in summer 2005, alongside a handful of other scrappy early bets. It took nineteen years, several ownership changes, and a lot of internet culture to get there, but Reddit finally went public in 2024. It's the longest gap on this list between "funded by YC" and "actually cashed out," and a reminder that some of these bets take two decades to pay off.
7. Dropbox — the file-sync company that proved the model could work at all
Drew Houston and Arash Ferdowsi built Dropbox to solve Houston's own problem of forgetting USB drives, and it became one of YC's first genuinely large exits when it went public in 2018. It doesn't get the same headline attention as the consumer marketplace names above it, but it's foundational to YC's origin story — an early proof point that a batch program running out of a small office could actually produce companies worth billions.
8. Twitch — the pivot that worked better than the original idea
Twitch didn't start as Twitch. It started as Justin.tv, a lifecasting site that let one person stream his entire day online. The gaming-streaming vertical that grew out of it turned out to be the actual business, and Amazon bought it for roughly $970 million in 2014 — one of the cleanest examples on this list of a founding team following the data instead of the original pitch deck.
9. Cruise — autonomous vehicles, backed by Detroit
Cruise represents a different kind of YC outcome than most of this list: instead of an IPO or a full acquisition exit, it became a GM-backed subsidiary building autonomous vehicle technology, with billions in outside capital layered on top of its original YC seed. It's a useful reminder that "successful YC company" doesn't always mean "went public" — sometimes it means becoming the R&D engine inside a much older industrial giant.
10. Deel — the newest name to earn a spot on this list
Deel is the youngest company here by a wide margin, and its presence on this list is really a bet on trajectory rather than a settled outcome the way the public companies above it are. It built global payroll and compliance infrastructure for remote teams right as remote work became a permanent fixture rather than a pandemic footnote, and it's grown into one of the largest private unicorns to come out of YC in the years since — the clearest sign yet that the program's next great outcome doesn't have to look like the last one.
What the list actually tells you
A few patterns hold across all ten of these, and they're more useful than any individual company's story.
First, the power law is real and it's not subtle. YC has funded more than 4,000 companies and raised over $145 billion in follow-on funding across its portfolio, yet the top ten names here account for something like two-thirds of all the value ever created. Most YC companies don't become Stripe. Most don't need to — but the ones evaluating "is this accelerator worth it" should understand exactly how concentrated the outcomes actually are.
Second, consumer bets built the early value, and infrastructure bets are building the current value. Airbnb, DoorDash, Instacart, and Reddit all rode the shift to mobile in the 2010s. Stripe, the single largest name on this list, is a plumbing company — unglamorous, essential, and now worth more than any of the consumer names it shares a portfolio with.
Frequently asked questions
Is Stripe really more valuable than Airbnb?
Yes, at least by their most recent respective valuations — Stripe's $159 billion private valuation from February 2026 exceeds Airbnb's $86.5 billion IPO valuation, though Airbnb's current public market cap moves daily and is worth checking independently.
Was Reddit actually one of YC's first companies?
Yes. Reddit was part of Y Combinator's very first batch in summer 2005, making it one of the longest-running examples of a YC company on this list, even though it didn't go public until 2024.
Why isn't OpenAI or another major AI company on this list?
This ranking covers companies actually built inside YC's accelerator program. Sam Altman later served as YC's president, and the firm has backed several major AI companies since, but the direct-graduate list here is built around the accelerator's own founded-and-funded portfolio.
What's the most likely candidate to join this list next?
Deel is the strongest current candidate given its growth trajectory, and several more recent YC batches — including ones with AI infrastructure and agentic AI companies — are being watched closely as potential future entrants, though none has reached the scale of the ten companies here yet.
The bottom line
Twenty years in, Y Combinator's actual track record looks less like a diversified fund and more like a handful of genuinely category-defining bets that happened to come out of the same small program: a payments company that quietly became more valuable than most banks, a handful of consumer marketplaces that reshaped entire industries, and one accelerator batch from 2005 that, without anyone realizing it at the time, contained the future front page of the internet.
Further reading on this topic
We'll revisit this ranking as newer YC batches mature and current private valuations shift. Check the Startups section for updates.
Valuation and market cap figures referenced in this article reflect public reporting, company disclosures, and third-party financial data providers (Sacra, CB Insights, MacroTrends, Capital.com) available as of the publish date. Public company market caps fluctuate daily and private valuations reflect the most recent known funding or tender event, not real-time figures. Verify current figures directly before citing them elsewhere. This article does not contain affiliate links; where future articles do, they will be disclosed per our Affiliate Disclosure.