Published: 2025-12-22 by Luca Dellanna
What is ergodicity and why does it matter? Learn how irreversible outcomes affect long-term performance in investing, business, and life decisions.
"One of the most important books I've read, period. It's short, articulate, and expansive on a singular subject matter — ergodicity, which is really the key ingredient to success in life, marriage, business, family, happiness, health, etc."
Blake Janover
CEO, Janover Inc.
"One of the most important books for everyone to read. Ergodicity should be taught in school and it should be a common metric in businesses that leaders pay attention to and are deliberate about."
Matt Cannon
"A fascinating book […] Once I started, I couldn't put it down […] the math is minimal, and Luca treats the subject well. I wish I had read it two years earlier"
Robert Matthews
VP of Engineering, Equifax
"One of the very best books I read about risk management. A must read."
Alessandro Francescotto
Partner, Excellence Consulting
"Profoundly insightful [...] If you are someone who often needs to make decisions under uncertainty and using incomplete information (which I think applies to most of us), then Ergodicity is a must-read."
Dev Ashish
StableInvestor Founder
"Brilliant. Must read."
N. S. Ramnath
Journalist & Author
"A brilliant, concise, thought-provoking gem. A must-read for investors."
Rakesh
Investor
"A great book for those who quickly want to familiarize themselves with the concept of ergodicity. The author goes to great lengths explaining the concept in easily understandable terms. Highly recommended!"
Auke Hunneman
BI Norwegian Business School
"It helped clarify several longstanding pragmatic questions I had about uncertainty and risk [...] a lucid explanation, accessible for a general audience."
Pankaj Saikia
Datafarer co-founder.
"Excellent book. Highly recommended. Luca compresses a lot of wisdom and actionable guidance into few words. No fluff, no fillers, only thought through foundational ideas."
Eleanor Berger
AI consultant
“Take risks early in your career” is common advice. But not all risks are equal. Some career moves are reversible experiments; others can permanently damage your trajectory.
Ergodicity helps distinguish between them.
These risks have outcomes you can recover from:
With these moves, bad outcomes don’t prevent you from trying again. Over time, your results converge toward the expected value.
These risks can cause lasting damage:
With these moves, a single bad outcome can permanently alter your trajectory. The “expected value” is meaningless if one bad roll ends the game.
Ergodic: Joining a startup as an employee
Non-ergodic: Putting your life savings into your own startup
Strategy: Take calculated startup risks where the downside is time and learning, not financial ruin.
Ergodic: Giving talks at industry events
Non-ergodic: Making public statements that could be career-ending
Strategy: Build visibility gradually through recoverable actions.
Ergodic: Occasional professional disagreements
Non-ergodic: Burning bridges when leaving
Strategy: Always leave doors open, even when frustrated.
Remember the two skiers? A 0.1% daily risk seems negligible, but over a 40-year career, it becomes near-certain.
The same applies to career risks:
| Daily Risk | After 1 Year | After 10 Years | After 40 Years |
|---|---|---|---|
| 0.01% | 96.4% safe | 69.4% safe | 23.2% safe |
| 0.1% | 69.4% safe | 2.6% safe | ~0% safe |
| 1% | 2.6% safe | ~0% safe | ~0% safe |
Small, repeated exposure to non-ergodic risks eventually catches up with you.
Take lots of small, recoverable risks:
Protect against catastrophic outcomes:
Create systems that make you more resilient:
