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.
Growth is not always a good thing if it requires too much capital.
Far more money has been lost by investors preparing for corrections than has been lost in the corrections themselves.
The investor should be guided by long-term considerations and not by short-term market fluctuations.
I want to be able to make mistakes, to pay too much sometimes, and still do fine over time.
When a manager with a great reputation meets a business with a bad reputation, it's usually the business that wins.
Market declines are great opportunities to buy stocks at bargain prices.
The investor should periodically rebalance his portfolio to maintain the desired asset allocation.
We will always be prepared for the thousand-year flood. In fact, if it occurs we will be selling life jackets to the unp...
I don't want to do business with people I don't trust.
In this business, if you're good, you're right six times out of ten.
The defensive investor will avoid the temptation to stray into the unknown in search of higher returns.
It is remarkable how much long-term advantage people like us have gotten by trying to be consistently not stupid, instea...
I don't invest in what I don't understand.
Nobody can predict interest rates, the future direction of the economy, or the stock market.
An index fund is the best choice for the investor who cannot or does not want to devote time to security selection.
Only when the tide goes out do you discover who's been swimming naked.
Over the long term, it's hard for a stock to earn a much better return than the business which underlies it earns.
Sell if you find something better.
The simplest policy for the defensive investor is to invest a fixed amount at regular intervals.
Wide diversification is only required when investors do not understand what they are doing.
The single most important decision in evaluating a business is pricing power.
Diworsification—when a company diversifies into unrelated areas—is a bad sign.
The defensive investor must confine himself to the shares of important companies with a long record of profitable operat...
Cash combined with courage in a crisis is priceless.
I want to know how the sausage is made.
Heavy insider selling is a warning sign.
Qualitative factors are those related to the nature of the business, the competitive situation, and management.
I've seen more people fail because of liquor and leverage — leverage being borrowed money — than any other reason.
The way to win is to work and hope for a long life.
Sell cyclicals when inventories are building and the economy is booming.
Explore core insights from different masters across investment topics