Principles

Every idea worth keeping, in plain English. Search them, flip through them as cards, or read each rule beside where it flips. Every principle carries the case where it misleads - a lens you meet at the moment of use, not a bookshelf.

330 principles · plain-English, in our own words

Survival first

42You cannot come back from zero - so never risk being taken out of the game.

Margin of safety & sizing

18Leave room to be wrong, spread your bets, and never bet more than your edge.

Your own mind

34The predictable biases that quietly cost you money.

Temperament & enough

45Character beats cleverness; knowing what enough is beats chasing more.

How to decide

46Judge the decision, not the outcome - good process survives bad luck.

Do your own homework

28Read the primary source, know what you own, and follow the incentive.

Costs, simplicity & compounding

23Small certain drags - fees, taxes, churn - decide long-run wealth. The boring default wins.

What it's worth

53Price is what you pay, value is what you get - and telling them apart is the whole game.

Markets & cycles

29Crowds, cycles and bubbles - the weather the individual investor sits inside.

Price & charts

12What price, trend and volume can - and cannot - tell you about what comes next.