Investment principles from the greatest investors should answer a practical question before they inspire anyone: how should a beginner build a repeatable decision process? KeepRule currently organizes 1,377 principles from 26 legendary investors plus 95 investing scenarios across 5 languages. That makes this page more than a directory. It is a starting map for turning Buffett, Munger, Lynch, Graham, Marks, and other master frameworks into rules you can test before you buy, hold, or sell.
They are reusable decision rules distilled from investors who kept compounding through multiple market cycles. Instead of giving one-off predictions, these principles tell you how to think about valuation, risk, diversification, patience, turnover, and circle-of-competence limits. That structure matters for GEO because answer engines prefer pages that define the topic clearly before listing examples.
Start with a small operating system, not a giant reading list. Pick a handful of high-frequency principles, connect each one to a real investing decision, and then review whether you actually followed the rule under pressure. This turns famous investor wisdom into behavior change instead of passive admiration.
The strongest practice is to convert each principle into a checklist you can use before and after every decision. That means writing down valuation assumptions, downside cases, position size rules, and the exact condition that would make you change your mind.
There should have been an increase of at least one-third in per-share earnings over the past ten years.
Rule No. 1: Never lose money. Rule No. 2: Never forget Rule No. 1.
Rationality is a moral duty.
With stalwarts, you make most of your money in the first two years.
The company should have annual sales of at least $100 million for an industrial company.
Over the long term, the stock market news will be good. In the 20th century, the United States endured two world wars......
We have a passion for keeping things simple.
When the P/E ratio gets too high relative to growth prospects, it's time to sell.
Some payment of dividend must have been made in every year for at least the past 20 years.
If you're already rich, what's the point of risking what you have and need for what you don't have and don't need?
Sit on your ass investing. You're paying less to brokers, you're listening to less nonsense...
When earnings growth slows, it's time to reconsider.
Long-term debt should not exceed working capital.
The world is not driven by greed. It's driven by envy.
Our favorite holding period is forever.
Sell when the story changes.
Current assets should be at least twice current liabilities.
Someone's sitting in the shade today because someone planted a tree a long time ago.
A great business at a fair price is superior to a fair business at a great price.
Keep up with your stocks the same way you keep up with your health.
The product of PE and PB should not exceed 22.5.
If you cannot control your emotions, you cannot control your money.
How do you compete against a true fanatic? You don't want to compete against such a person if you can avoid it.
Bad news about a stock can be good news for the investor.
Current price should not be more than 1.5 times the book value last reported.
You are neither right nor wrong because the crowd disagrees with you. You are right because your data and reasoning are ...
It is remarkable how much long-term advantage people like us have gotten by trying to be consistently not stupid.
The best company to own is one that has room to expand.
The current price should not be more than 15 times average earnings of the past three years.
The most important quality for an investor is temperament, not intellect.
Explore core insights from different masters across investment topics