Y Combinator
| Company type | Private |
|---|---|
| Industry | Technology startup accelerator, Venture capital |
| Founded | March 2005 |
| Founder | Paul Graham, Jessica Livingston, Robert Tappan Morris, Trevor Blackwell |
| Headquarters | San Francisco , United States |
Area served | Global |
Key people | Garry Tan (President and CEO), Jessica Livingston (Co-founder), Michael Seibel (former Managing Director) |
| Products | Startup acceleration, Seed funding, Venture capital investment |
| Website | www |
Y Combinator, LLC (YC) is a prominent American technology startup accelerator and venture capital entity established in March 2005. It has facilitated the creation of more than 5,000 companies. Initially launched in Boston and Mountain View, YC expanded its presence to San Francisco in 2019 and transitioned to a fully virtual model amid the COVID-19 pandemic. Among the distinguished startups supported by YC are Airbnb, Coinbase, Cruise, DoorDash, Dropbox, Instacart, Reddit, Stripe, Scale AI, Deel, Helion Energy, and Twitch.
History
Y Combinator was founded in 2005 by Paul Graham, Jessica Livingston, Robert Tappan Morris, and Trevor Blackwell. The accelerator commenced its programs in both Cambridge, Massachusetts and Mountain View, California. Due to operational difficulties, YC centralized its activities in Silicon Valley by 2009.
Jessica Livingston played a pivotal role in defining YC’s culture and achievements, overseeing daily operations and the selection process for founders.
In 2009, YC raised $2 million through an investment round led by Sequoia Capital, which enabled it to increase annual funding to roughly 60 startups. Sequoia further supported YC with an $8.25 million infusion in 2010, aiding its expansion. Kirsty Nathoo joined as an accountant and was promoted to CFO in 2012. In 2011, investors including Yuri Milner and SV Angel extended a $150,000 convertible note offer to every YC company; this amount was later revised to $80,000 alongside the renewal of the Start Fund.
Advisors such as Harj Taggar and Alexis Ohanian became involved in 2010; Taggar and Paul Buchheit were elevated to partner status within the same year. By 2014, Michael Seibel had become a full-time partner. Starting in 2013, YC began investing in nonprofit ventures after piloting with organizations like Watsi. In 2014, former YC founder from its inaugural batch, Sam Altman, was appointed President and introduced an updated investment structure: $150,000 for a 7% equity stake.
The year 2016 marked YC’s international expansion with visits to eleven countries aimed at connecting with global founders. Altman stepped back into a founder role working on OpenAI, while leadership responsibilities were assigned to Ali Rowghani (heading YC Continuity) and Seibel (leading YC Core). In 2017, Startup School was launched, providing online educational resources and mentorship to over 1,500 startups during its first year.
A software malfunction in 2018 resulted in the acceptance of approximately 15,000 startups into Startup School; YC ultimately accommodated all affected participants. That same year saw former Microsoft Bing CEO Qi Lu briefly lead YC China before its discontinuation; this initiative later transformed into the accelerator known as MiraclePlus, directed by Lu.
In 2019, Geoff Ralston took over from Altman as president. With the onset of the COVID-19 pandemic in 2020, YC adapted by conducting remote batches. January 2022 introduced a revised standard deal comprising $500,000 total funding—$125,000 for 7% equity plus $375,000 via an uncapped safe featuring a Most Favored Nation provision. The summer cohort of that year was reduced by 40%, shrinking from 414 to 250 startups.
In January 2023, leadership transitioned to Garry Tan as president and CEO following Ralston’s departure; under Tan’s guidance, the YC Continuity growth fund was phased out. After deliberations beginning in 2019, YC moved its headquarters from Mountain View to San Francisco during spring 2023.
In March 2024, Michael Seibel resigned from his role as managing director.
Programs
Y Combinator conducts four cohorts of startups each year. Participating startups are granted $500,000 in seed capital: $125,000 in exchange for 7% equity through a post-money SAFE, plus an additional $375,000 via an uncapped SAFE featuring a "most favored nation" clause. Non-profit organizations receive donations amounting to $100,000. The program offers personalized "office hours," group workshops, and weekly sessions with entrepreneurs and investors based in Silicon Valley.
The accelerator emphasizes areas such as marketing strategies, team development, business model optimization, attaining product/market fit, and scaling ventures into rapidly growing enterprises. The program concludes with "Demo Day," during which startups present their pitches to prospective investors.
Y Combinator also provides follow-up initiatives for its alumni companies, including the Series A Program, YC Post-A Program, and YC Growth Program, which focus on firms pursuing Series B funding rounds ranging from $20 million to $100 million.
Additional initiatives introduced since 2015 include:
- The YC Fellowship Program (2015), designed for earlier-stage startups. Initially, it offered grants without equity; this later shifted to $20,000 for 1.5% equity convertible upon IPO or major acquisition. This fellowship was discontinued in 2017.
- The YC Continuity Fund (2015) allowed pro rata investments in alumni companies but was terminated in March 2023.
- From 2017 to 2019, Y Combinator launched several programs such as Startup School, the Series A program, the Growth program, Work at a Startup, and YC China.
By 2025, Y Combinator had invested in more than 5,000 companies with an aggregate valuation of approximately $600 billion. While the majority are for-profit ventures, some non-profit organizations like Watsi and Women Who Code have also participated in the core program.
Research
In October 2015, Y Combinator initiated YC Research to support long-term foundational research efforts, backed by a $10 million donation from Sam Altman. Researchers were employed full-time and had the opportunity to obtain equity stakes in Y Combinator.
The first project under YC Research was OpenAI, followed by investigations into basic income and innovative urban development concepts. Established in 2016, the Human Advancement Research Community (HARC) aimed to ensure that human wisdom would surpass human power. Inspired by discussions between Altman and Alan Kay, HARC concentrated on modeling techniques, visualization tools, educational software, and programming languages. Prominent participants included Alan Kay, Dan Ingalls, Bret Victor, Vi Hart, and Patrick Scaglia. HARC was discontinued in 2017.
Australian quantum physicist Michael Nielsen served as a research fellow at YC Research from 2016 until 2019.
In 2020, YC Research separated from Y Combinator and was rebranded as Open Research.
See also
- List of Y Combinator startups
- Hacker News
- Techstars
- 500 Startups
- HighTechXL
- Entrepreneurs Roundtable Accelerator
- Forum Ventures
External links
- Wonderful Performance, formerly known as Y Combinator China
- Articles with short description
- Y Combinator
- Business incubators of the United States
- Startup accelerators
- Venture capital firms of the United States
- Financial services companies based in California
- Companies based in San Francisco
- Financial services companies established in 2005
- 2005 establishments in California
- Business incubators