The Most Hyped YC-Backed Startups in the US
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The short answer
The most hyped Y Combinator–backed startups in the US right now span fintech, crypto, logistics, and a fast-growing wave of AI. This list covers fifteen of the most talked-about — Stripe, Scale AI, Deel, Coinbase, Reddit, Brex, Airbnb, DoorDash, Instacart, Faire, Vanta, Replit, Supabase, Whatnot, and Retell AI — with who founded each, what they build, and why they're worth watching in
Y Combinator has funded thousands of startups since 2005, and a striking number of the companies defining American tech came out of its batches. Below are fifteen of the most hyped YC-backed startups headquartered in the US — the ones investors, operators, and founders keep bringing up. It's not a strict ranking; every company here is among the most discussed in its category
| Company | What they build | Sector |
|---|---|---|
| Stripe (S09) | Payments and financial infrastructure for the internet | Fintech |
| Scale AI (S16) | Data labelling and evaluation for AI models | AI infrastructure |
| Deel (W19) | Global payroll, hiring and compliance | HR tech |
| Coinbase (S12) | Crypto exchange and custody, publicly listed | Crypto |
| Reddit (S05) | Community platform, publicly listed | Consumer internet |
| Brex (W17) | Corporate cards and spend management for startups | Fintech |
| Airbnb (W09) | Global marketplace for stays and experiences | Marketplace |
| DoorDash (S13) | Local delivery and logistics network | Delivery |
| Instacart (S12) | Grocery delivery and retail media | E-commerce |
| Faire (W17) | Wholesale marketplace for independent retailers | Marketplace |
| Vanta (W18) | Automated security compliance (SOC 2, ISO) | Security SaaS |
| Replit (W18) | Browser-based coding and AI app building | Developer tools |
| Supabase (S20) | Open-source Postgres backend for developers | Developer tools |
| Whatnot (W20) | Live shopping and auctions for collectors | Live commerce |
| Retell AI (W24) | Voice AI agents for phone calls | AI agents |
The most hyped YC-backed US startups in
1. Stripe (YC S09)
Stripe is the payments infrastructure a huge share of the internet quietly runs on, built by Irish brothers Patrick and John Collison. It remains the most valuable company Y Combinator has ever funded and one of the most closely watched IPO candidates in all of tech. Visitstripe.com
2. Scale AI (YC S16)
Founded by Alexandr Wang and Lucy Guo, Scale AI provides the data infrastructure used to train the world's AI models. In 2025 Meta took a roughly 49% stake valuing the company at $14.3 billion and brought Wang in to lead its superintelligence effort — one of the defining deals of the AI era. Visitscale.com
3. Deel (YC W19)
Deel, started by Alex Bouaziz and Shuo Wang, handles global payroll, hiring, and compliance across 150+ countries. One of the fastest-growing software companies ever, it was valued around $17.3 billion in 2025. Visitdeel.com
4. Coinbase (YC S12)
Brian Armstrong and Fred Ehrsam built Coinbase into the largest crypto exchange in the US. Now public on the Nasdaq, it joined the S&P 500 in 2025 — a first for a crypto company. Visitcoinbase.com
5. Reddit (YC S05)
One of the very first companies YC ever backed, Reddit was co-founded by Steve Huffman and Alexis Ohanian. It went public in 2024 and has become central to the AI story through high-profile data-licensing deals with the largest model makers. Visitreddit.com
6. Brex (YC W17)
Henrique Dubugras and Pedro Franceschi were barely out of their teens when they launched Brex — corporate cards and spend management built for startups and, increasingly, enterprises. It's now a multi-billion-dollar fintech. Visitbrex.com
7. Airbnb (YC W09)
The original YC breakout, Airbnb was founded by Brian Chesky, Joe Gebbia, and Nathan Blecharczyk after they rented out air mattresses to make rent. It's now a public company all but synonymous with travel. Visitairbnb.com
8. DoorDash (YC S13)
Tony Xu, Stanley Tang, Andy Fang, and Evan Moore started DoorDash as a Stanford project. Today it's the largest food-delivery platform in the US, public and part of the S&P 500, now pushing into advertising and autonomy. Visitdoordash.com
9. Instacart (YC S12)
Founded by Apoorva Mehta, Instacart turned same-day grocery delivery into a category of its own. It went public in 2023 and is now leaning hard into high-margin retail-media advertising. Visitinstacart.com
10. Faire (YC W17)
Max Rhodes and his co-founders built Faire into the wholesale marketplace connecting independent retailers with the brands that stock their shelves — a multi-billion-dollar business now expanding across the globe. Visitfaire.com
11. Vanta (YC W18)
Christina Cacioppo founded Vanta to automate the security and compliance work — SOC 2, ISO 27001, and the rest — that every software company dreads. It's become the category leader as compliance goes AI-native. Visitvanta.com
12. Replit (YC W18)
Amjad Masad's Replit lets anyone build software right in the browser — and its AI agent turned "vibe coding" into one of 2025's biggest developer stories, bringing app-building to millions who'd never written a line of code. Visitreplit.com
13. Supabase (YC S20)
Paul Copplestone and Ant Wilson's Supabase is the open-source "Firebase alternative" that has quietly become the default backend behind the AI app-builder boom, powering millions of developers. Visitsupabase.com
14. Whatnot (YC W20)
Grant LaFontaine and Logan Head built Whatnot into the largest livestream-shopping platform in the US, where collectors and fans buy everything from trading cards to fashion in real time. Visitwhatnot.com
15. Retell AI (YC W24)
One of the freshest names on this list, Retell AI — founded by Todd Li and his team — gives companies an API to build human-sounding voice agents, a breakout of the 2024–25 wave of AI that can actually pick up the phone. Visitretellai.com
What the most hyped YC startups have in common
Beyond the batches and the valuations, the hyped YC companies share something quieter: their founders are visible. Patrick Collison, Alexis Ohanian, Amjad Masad, Ryan Petersen, Alexandr Wang — these are names people follow, not just companies. The audience a founder builds becomes a distribution channel the company owns outrighta distribution channel the company owns outright
It's not a coincidence. In a crowded market, the founder's own voice is often the fastest way to earn trust with customers, candidates, and investors at once — which is exactly what many investors now look forwhat many investors now look for
Frequently asked questions
What does "YC-backed" mean
A YC-backed startup has been through Y Combinator, the Silicon Valley accelerator that invests in early-stage companies in twice-yearly batches — labeled like S16 (Summer 2016) or W24 (Winter 2024) — and has funded thousands of startups since 2005
What is the most valuable YC-backed startup
Stripe is the most valuable company Y Combinator has funded, worth tens of billions of dollars and widely considered one of the most anticipated future IPOs in technology
Are these YC startups still private
Some are public — Airbnb, Coinbase, DoorDash, Instacart, and Reddit all trade on public markets — while others like Stripe, Deel, Brex, Faire, and Vanta remain privately held
Where are most of these YC startups based
The majority are in the San Francisco Bay Area, though many YC companies are now remote-first and US-incorporated while operating globally. New York and Los Angeles also appear on the list, with OpenSea and Whatnot respectively
How do YC startups get so much attention
Strong products and big funding rounds help, but many YC founders also build large personal audiences on X and LinkedIn — which amplifies every launch, hire, and milestone far beyond what paid marketing could buy
Which is the newest startup on this list
Retell AI (YC W24) is the most recent, part of the current wave of AI voice-agent companies that emerged in 2024 and 2025
The bottom line
The most hyped YC companies span payments, crypto, logistics, and now a fast-growing cluster of AI — but the throughline is founders who built something people talk about, and then made sure people heard about it., the founder's presence is as much a part of the company as the product
At Invisible Keyboard, we run founder and team content for exactly these kinds of companies — so a founder's presence compounds without the founder having to do the workwe run founder and team content