If founder mode says the pure people manager is finished, that means the founder has to build the thing and negotiate the deal, close the skeptical buyer, deliver the feedback nobody wants to give, and more. That's a lot to learn. So how are founders doing it? They’re hitting the bookstore.

We examined book spend on Brex across all customers, and founder mode is written all over the receipts.

A year ago, operating manuals were the most-purchased books. In the first half of 2026, a biography of Alex Karp, the co-founder and CEO of Palantir tops the list, followed by a wave of books about the work founders won't hand off.

Leaders are going full founder mode by devouring books about builders who are changing the world, from defense systems to restaurant empires to battlefields.

The 25 books founders buy most on Brex

Data is for H1 2026
Movement = change in rank vs. the same window a year ago (H1 2025).
NEW = no appearance a year ago

Honorable mentions

A few titles sitting just outside the top 25 that belong in this story:

• The Technological Republic (Alex Karp & Nicholas Zamiska). The most-purchased business book of 2026 is about Alex Karp, and his own book, the argument for what Silicon Valley owes the country that built it, is knocking on the door of the same list.
• The Infinity Machine (Sebastian Mallaby): The AI-builder bookshelf is growing. First the oral history of AI landed at #10, and now the biography of the man behind DeepMind is climbing right behind it.
• Zero to One (Peter Thiel). Published in 2014 and back in the top 40 after a year off, it still resonates with the founder worldview: don't compete, don't copy, build the thing only you can see.
• An Elegant Puzzle (Will Larson) and The Art of Doing Science and Engineering (Richard Hamming). Two more Stripe Press hardcovers are within arm's reach of the top 25 list. More on that below.

Founders are reading books by and about founders

Startup readers want to learn from the founders themselves. A playbook might tell you how to run the company, but the biographies tell you who you have to become to run it.

These founder and CEO biographies trended up this year:

• #1, The Philosopher in the Valley (Steinberger, Nov '25). The Karp biography reveals Karp has no business background and no computer-science background. He’s severely dyslexic, allergic to the standard CEO script, and reliably willing to say things in public most operators wouldn't whisper. The book showed up in November and went straight to the top of this list by a wide margin.
• #9, The Hard Thing About Hard Things (Horowitz). At 12 years old, this book is up 41% from a year ago, climbing five spots into the top 10. No book is more honest about how ugly building a company gets, and apparently every new cohort of founders figures that out on schedule.
• #13, High Output Management (Grove). This book defined how Silicon Valley ran teams for four decades. It rose 59% and climbed twelve spots. This is the book that started founders sharing their opinionated view on how companies should run. Founders are reading Grove and the biographies at the same time to develop their own mix of the methods.

The skills you can't delegate

The first wave of founder-as-personal-project reading hit a ceiling. Everyone bought Atomic Habits, everyone built a morning routine, and a lot of those routines faded. The whole optimize-yourself shelf lost ground at once:

• A year ago, Atomic Habits was the #3 book on this list. Today it's #11, down 31%.
• Extreme Ownership fell from #10 to #19.
• What the Heck Is EOS? slid six spots.

What's pulling away: hard feedback, skeptical buyers, coaching conversations. These are the skills of someone who does the work, not someone who manages it.

• Never Split the Difference: up four spots to 7, up 57% from a year ago.
• Crucial Conversations: up twenty spots to 14, up 76%, the biggest climb on the list.
• The Challenger Sale: up 50%, now #5. Radical Candor: up 35%, inside the top 10.
• Dare to Lead and The Coaching Habit: up thirteen and sixteen spots.

The #3 book startups buy

The Scaling Era, Dwarkesh Patel's oral history of how the models actually got built, with Dario Amodei, Demis Hassabis, Ilya Sutskever, Mark Zuckerberg, and others, debuted at #10. And Designing Data-Intensive Applications, a 700-page distributed-systems textbook, is tied for third, up 44% from a year ago. A systems engineering textbook is the #3 book among founders.

The people running companies are reading the deep technical material themselves, because in founder mode there's no layer between them and the machine.

Stripe Press has won the startup bookshelf

Stripe launched its press in 2018 with a handful of titles a year, betting that operators would pay for beautifully made hardcovers about science, economics, and technology. Books for "an audience that is global, fiercely curious, and extremely high-agency," in their own words. A leading global payments company is now outperforming 200 year old publishers.

Three of the top 25 are Stripe Press hardcovers, and two more are in the honorable mentions:

• #10, The Scaling Era (Dwarkesh Patel, NEW)
• #12, Scaling People (Claire Hughes Johnson, +17% from a year ago)
• #21, The Origins of Efficiency (Brian Potter, NEW)

Just outside the top 25: An Elegant Puzzle (Will Larson) and The Art of Doing Science and Engineering (Richard Hamming)

Closing

Founder mode has animated two years of podcasts, panels, and essays, and for good reason. It's a leadership idea that came from founders themselves, not the theory shelf. The Brex data adds something new to that conversation: whatever founders say, they also vote with their corporate cards. They've picked up the founders who came before them, the story of how the machines they now command got built, and they're still reading Grove while they do it.

So compare your bookshelf to the list. Are you operating the way the data says founders operate now or are you still reading the faders?

Methodology

Rankings come from anonymized Brex card purchases of books tagged by ISBN. The ISBN-level detail comes from L2/L3 card data that Brex uses to auto-generate itemized receipts on purchases like these, so customers don't waste time uploading them. We count cardholder purchases per month and sum across each period. For momentum, we compare each title's rank in H1 2026 to the same window a year earlier, which controls for the seasonality of when companies buy books.

Sumeet Marwaha is the Head of Data at Brex, supporting Brex in understanding how customers spend, adopt tools, and grow their businesses.

All analysis conducted for this report that uses Brex internal customer data is anonymized and aggregated for privacy. To learn more about how we use data in anonymized or aggregated form for these trend reports, email us at privacy@brex.com.