Stanford’s ‘How to Start a Startup’ series

Y Combinator changed the way startups around the world are built

Many of the philosophies that the leaders of Y Combinator have infused into the program’s portfolio companies have become the playbook for building the next big thing, such as its focus on founder personality and more.

Visualize where the first batch of founders from the famous startup accelerator Y Combinator are now.

Listen to a podcast episode where Y Combinator CEO Gary Tan explains why YC tends to outperform many other Silicon Valley startup accelerators.

Y Combinator cofounder Paul Graham keeps a public archive of his insightful essays

In addition to cofounding Y Combinator and other companies before it, Paul Graham is a prolific writer and artist. He chronicled many of his thoughts while building Y Combinator in a series of dozens of candid essays, all of which you can read in an online archive.

Read Paul Graham’s initial post announcing YC’s first batch

In March 2005, Y Combinator cofounder Paul Graham announced the program that would become Y Combinator on his website.

Sam Altman gave his first-ever startup pitch after dropping out of Stanford

He dropped out of Stanford to start Loopt, which sold in 2012 for $43.4M. You can watch his first-ever startup pitch in a video.

Stanford and Harvard are among the universities producing the most startup founders

Not all startup founders are created equal. This data visualization of the universities that produce the most startup founders is based on the number of alumni who have raised venture capital funding for their companies. That means these alums had to do much more than put "entrepreneur" in their LinkedIn bio to be considered startup founders.

Y Combinator was founded in 2005 to bridge gaps between founders and investors

In one of Paul Graham’s essays on his website, he took the time to explain how and why he and his cofounders (including his girlfriend at the time, and now wife, Jessica Livingston), came up with the idea of and eventually created Y Combinator.

Startup accelerators offer mentorship and seed funding in exchange for equity

Those programs, such as Y Combinator and Techstars, not only offer expert advice to founders, but also seed funding in exchange for equity. The goal is to help young startups learn from successful companies, making it more likely they attract venture capital.

Startup accelerators that include more training activities, such as pitch competitions, tend to have better long-term success rates

That's according to a new study from Wharton. Y-Combinator, perhaps the most famous startup accelerator, currently has 16 alumni companies trading on the public market. But not every entrepreneur who joins a startup accelerator makes it big.

Many startup founders pull out-of-the-box stunts to get their businesses off the ground.

The Y Combinator startup directory includes every company YC has funded

The startup accelerator has funded more than 5,000 companies over the years. This YC-specific search engine lets you look up any company to find out if it's a YC alum.

Y Combinator, the startup accelerator, gets its name from the 'Y combinator' computer science concept.

YC was partly inspired by an investor named Julian Weber

Y Combinator Cofounder Paul Graham’s former professor’s husband Julian Weber provided $10K in seed funding to Graham’s previous startup, Viaweb in its early days. In exchange, Weber received 10% of the company. Weber’s involvement inspired Graham to start a program where investors were more involved with the companies they contributed seed funding to.

'Founder mode' is the idea that startup founders should take a hands-on approach to running their businesses

In 2024, Y Combinator cofounder Paul Graham popularized the idea of "founder mode" when he wrote a viral manifesto in response to a talk that Airbnb CEO Brian Chesky gave about leadership styles. Graham positioned the concept of founder mode as the opposite of manager mode—when founders hire executives and middle managers to run their companies and make decisions that Graham says are better left to founders.

CEO Gary Tan explains Y Combinators guiding philosophy

Hear YC President and CEO Garry Tan talk about why he values earnesty and excellent communication skills in YC founders, his thoughts on AI, and more in this unexpectedly deep and in-depth interview.

Meet Frederick Terman: Stanford University professor and the 'Father of Silicon Valley'

Stanford University professor Frederick Terman used to encourage his students to start their own tech companies. His advice led to the creation of Hewlett-Packard. He also established the Stanford Research Park, which helped develop many successful tech companies today. Terman is often called the "Father of Silicon Valley," because his ideology directly shaped the region's development.

'Founder mode' is the idea that founders should take a hands-on approach to running their businesses

In 2024, Y Combinator Cofounder Paul Graham wrote a viral manifesto of sorts about a strategy he calls "founder mode." It's the opposite of what Graham calls "manager mode," which allows founders to hire executives who he says ultimately run the company into the ground.

The term 'startup'—which is typically used to describe private companies in their early stages of operation that focus on innovating new products or services to meet a market gap—can be traced back to a 1976 Forbes article.

Elon Musk's will to launch: the early days of SpaceX

Radically reducing the cost of rockets and innovating totally new space vehicles originated in the singular force of Elon Musk's vision. In this podcast, Founders creator David Senra shares what he learned reading a book about SpaceX's beginnings, highlighting Musk's audacious refusal to follow industry conventions and promotion of a culture of action and speed. Learn more insights from the founder here.

‘Demo days’ are when founders at Y Combinator pitch their startup ideas

Investors sit in the audience, waiting to hear what this season’s batch of YC founders have cooked up. YC argues that going through the process of a demo day can help founders get a better understanding of their startup themselves.

Y Combinator cofounder, Jessica Livingston, once interviewed her husband and cofounder, Paul Graham

Two of Y Combinator's cofounders, Jessica Livingston and Paul Graham, were in a romantic relationship before they started the accelerator. They later married, and much later, Livingston started a podcast. In an episode of her podcast, Livingston and her cohost interview Graham about the beginning of YC and more.

Read Sam Altman's life advice that he wrote in a blog post before he became CEO of OpenAI, from "don't lose touch with old friends" to "occasionally stay up until the sun rises talking to people."

Mark Zuckerberg credits some of Facebook's success to constant evolution

Before becoming the head of OpenAI, Sam Altman was the president of Y Combinator—a startup accelerator company that supported companies like Airbnb, DoorDash, and Coinbase. In 2016, Altman interviewed Zuckerberg about creating Facebook and its growth over time. Zuckerberg said that, unlike other companies (think: CourseMatch), Facebook kept growing and adding new features, which prevented the app from becoming obsolete.

For Reddit's founders, the company's early days included choosing a dinner with Y Combinator's Paul Graham over a spring break trip, a $10M Condé Nast acquisition, and other pivotal moments.

Y Combinator has a roughly 1% acceptance rate

That’s lower than the most elite universities and colleges in the world—but insiders have some tips about how applicants can have the best shot of being accepted to the selective startup accelerator.

See an analysis of the similarities between the characters in 'Silicon Valley' and the real people who inspired them

The HBO show "Silicon Valley" follows the story of an engineer who is trying to get his startup to take off in Silicon Valley. While one tech CEO said the show is like a documentary, many speculate the show is based on real life tech figures like Mark Zuckerberg and Peter Thiel.

87% of the startups in Y Combinator’s Fall 2025 batch were AI companies

Y Combinator also recently increased its number of cohorts or “batches” per year from two to four. Its leaders cited artificial intelligence’s rise as a reason for the increase.

Your iPhone started with a Cold War secret

Silicon Valley wasn't supposed to happen. A stretch of California orchard land somehow became the place that built the modern world: chips, PCs, the internet, the smartphone, and now AI. But the real story isn't the garage myth. It's a series of contradictions hiding in plain sight.

Silicon Valley’s reign over tech, money, and politics

Tesla and X CEO Elon Musk, OpenAI CEO Sam Altman, LinkedIn founder Reid Hoffman, and others are getting into politics. From Musk’s role in President Trump’s second term to Hoffman’s spending on former Vice President Harris’ presidential campaign, more tech CEOs are expanding into politics. This podcast episode by WBUR and American Public Media discusses what the impact could be with so many tech figures engaging in American politics. Listen here.

Working at a startup isn't for everyone, and is often more fast-paced than a run-of-the-mill job

Some argue that ideal startup employees have to be better than the average worker at managing uncertainty, acting with an "ownership" mindset rather than being a cog in the machine, and pushing limits.

How venture capital firms came to be

The venture capital firm that kickstarted an industry.

7 angel investors funded Google in its early days

Entrepreneur Shaan Puri shares how seven strangers acted as Google’s earliest angel investors. The first gave Google $100K without even putting his equity agreement in writing. The investors on “Shark Tank” use their personal funds to support startups, but they’re often more predatory about terms than typical angels.

Learn how eight 'traitors' played an essential role in founding Silicon Valley

In the 1950s, William Shockley led the way in the semiconductor business. Everything changed in 1957, after eight of his engineers—whom he called the "Traitorous Eight"—left his company to start their own. Their company, named Fairchild Semiconductor, employed many future founders of major Silicon Valley companies. Today, the Traitorous Eight are considered among the founders of Silicon Valley.

Andreessen Horowitz is among the most well-known venture capital firms

Also known as a16z, the firm has invested in companies such as Airbnb, Facebook, and Lyft since its founding in 2009. A podcast episode offers a deep dive into how the firm got started and became the industry disruptor it is today.

One office park had an outsized role in the birth of Silicon Valley

Developed in 1951, Stanford Research Park was more than just a pioneering suburban office park. It would go on to catalyze Silicon Valley's tech ecosystem as a whole.