Brad Feld

Brad Feld

Entrepreneur, author, and investor. Writing about startups, venture capital, books, and life since 2004.
A Rule of 40 heatmap by quarter from Q3 2023 to Q4 2025 for Formlabs, 3D Systems, and Stratasys. Formlabs climbs from negative scores into the green 25 to 49 percent range, while 3D Systems stays deeply negative and Stratasys hovers near zero.

Does the Rule of 40 Work for Hardware?

I've written about the Rule of 40 since 2015, and it's now gospel in SaaS. Does it mean anything for a company that makes physical things? Yes - but you have to read the curve, not the snapshot.

June 15, 2026 · 5 min · Brad Feld

Writing a Novel with Phin Argofy

I've written nine non-fiction books and have no idea if I can write a novel. I'm trying anyway: a crypto-thriller called Zero Knowledge, co-written with my AI, Phin Argofy.

June 13, 2026 · 5 min · Brad Feld

Phil Weiser For Colorado Governor

I'm good friends with Phil Weiser and Michael Bennet, and I think the world of both. Colorado wins either way. Here's why I think Phil is the right fit for the next four years.

June 8, 2026 · 3 min · Brad Feld

The Premise: The Lead User and the Machines That Build Machines

Eric von Hippel taught me that innovation comes from users, not manufacturers. My premise: all future end-user software innovation will come from the user, and the machines will build it.

May 29, 2026 · 5 min · Brad Feld
A golden retriever resting on the grass outdoors in the summer sun

It's Summertime

A summer weekend in Aspen - close friends, a gloriously bad movie, running again, and Phin Argofy quietly going autonomous in the work cave.

May 25, 2026 · 1 min · Brad Feld
How to Rule the World by Theo Baker

How to Rule the World

I read Theo Baker's How to Rule the World in the last 24 hours. It works on a lot of levels at once - memoir, investigation, a study in how power dismisses inconvenient reporting, and a master class in what not to do at the board level.

May 21, 2026 · 3 min · Brad Feld

The Cognitive Sport of Building Startups

Meru Health launched Advanced this month - the first integrated mental and physical health program built for founders. Why it matters, and why I invested.

May 14, 2026 · 3 min · Brad Feld
Burn Bright, Not Out book cover

Burn Bright, Not Out

For the month of May, I'm matching donations to the Kabila Founder Mental Health Fund. Plus a free chapter from a new book on founder mental health in tech startups.

May 1, 2026 · 2 min · Brad Feld

Give First, Build Right with Eric Ries

On April 29 at 10am PT, Eric Ries and I are doing a free fireside chat for startup communities. We're going to talk about the lessons we've learned as founders, investors, and advisors - and the books we've each just put into the world.

April 20, 2026 · 2 min · Brad Feld

I Built a Plugin Because Anthropic Won't Stop Shipping

Claude Code ships updates daily. My config breaks weekly. So I wrote a plugin that cross-references release notes against my setup.

March 29, 2026 · 3 min · Brad Feld