Investment Principles from the Greatest Investors

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.

26legendary investors
1,377principles indexed
95decision scenarios
5languages supported

What are investment principles from the greatest investors?

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.

How should someone get started with investment principles from the greatest investors?

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.

  1. Choose 3 to 5 principles you are likely to reuse in the next 90 days.
  2. Attach each principle to a real decision such as position size, valuation, diversification, or holding period.
  3. Cross-check the rule against the related master page, scenario page, and principle detail page instead of relying on one quote.
  4. Rewrite the idea as your own execution rule and review whether you followed it after each decision.

Evidence readers can cite

  • Coverage:KeepRule currently maps 1,377 principles from 26 masters plus 95 scenario explainers, giving beginners a concrete place to start instead of assembling scattered notes by hand. KeepRule llms.txt
  • Behavioral proof:Brad Barber and Terrance Odean analyzed accounts from more than 60,000 households and found that the 20% who traded most earned 10.0% annualized net returns versus 15.3% for the average household in the sample. That is a strong argument for learning principles before increasing activity. Barber & Odean, UC Berkeley
  • Diversification benchmark:The SEC’s beginner guide notes that owning only 4 or 5 individual stocks is not truly diversified and says investors may need at least a dozen carefully selected stocks to spread company-specific risk more effectively. SEC diversification guide
  • Cost discipline:Investor.gov’s fund-fee bulletin uses a simple example: a $10,000 purchase with a 5% front-end sales load leaves only $9,500 invested. Fees are not abstract; they are a direct drag on capital from day one. Investor.gov fee bulletin

What best practices help you apply these principles?

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.

  • Keep the first rule set small so you can execute it under stress.
  • Write down when each principle applies, when it fails, and what evidence would invalidate it.
  • Tie every rule to measurable variables such as valuation range, position size, downside risk, and review date.
  • Run a monthly review to separate process mistakes from normal short-term volatility.
🛡️📚 Benjamin Graham

Margin of Safety

The margin of safety is always dependent on the price paid.

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📌🔄 Howard Marks

Contrarianism

To achieve superior results, you have to hold non-consensus views about value, and they have to be accurate.

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📌⚖️ Ray Dalio

All-Weather Strategy

Structure your portfolio to perform well across all economic environments - growth, recession, inflation, and deflation.

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📌📖 John Templeton

Flexibility

It is impossible to produce superior performance unless you do something different from the majority. Be flexible in you...

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💼📖 Philip Fisher

Few Outstanding Investments

I don't want a lot of good investments; I want a few outstanding ones. Concentration in your best ideas is key.

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🎯📖 Seth Klarman

Patience

Patience is an essential virtue for value investors. The market will eventually recognize value, but the timing is uncer...

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📌📖 John Bogle

Don't Peek

Don't peek at your portfolio constantly. The more you look, the more likely you are to make an emotional mistake.

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💵🎩 Warren Buffett

One Dollar Test

Every dollar of retained earnings should create at least one dollar of market value.

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📌🧠 Charlie Munger

Critical Mass

You get huge advantages from scale.

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📌📈 Peter Lynch

Categories Change

Companies don't stay in one category forever.

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📝📚 Benjamin Graham

Lessons of History

Those who do not remember the past are condemned to repeat it.

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📌🔄 Howard Marks

Combating Negative Influences

The biggest investing errors come from psychological factors - greed, fear, envy, ego, and the desire to conform.

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📌⚖️ Ray Dalio

The Economic Machine

The economy works like a simple machine. Three main forces drive it: productivity growth, short-term debt cycle, and lon...

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📖📖 John Templeton

Research-Based Investing

Never buy a stock without thorough research. Know what you own and why you own it.

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💼📖 Philip Fisher

Hold Forever

If the job has been correctly done when a common stock is purchased, the time to sell it is almost never.

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🔍📖 Seth Klarman

Bottom-Up Analysis

We are bottom-up investors. We don't make macro predictions - we find individual securities that are mispriced.

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📜📖 John Bogle

Bond Allocation Rule

A rough rule: hold your age in bonds. A 30-year-old might hold 30% bonds, a 60-year-old 60% bonds.

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🏢🎩 Warren Buffett

Stock as Business Ownership

When we own portions of outstanding businesses with outstanding managements, our favorite holding period is forever.

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📌🧠 Charlie Munger

Permutations and Combinations

You have to learn the models in such a way that they become part of your repertoire.

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🏦📈 Peter Lynch

Asset Plays

An asset play is any company that's sitting on something valuable that the market has overlooked.

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💼📚 Benjamin Graham

Investment Requires Discipline

The investor's chief problem—and even his worst enemy—is likely to be himself.

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📌🔄 Howard Marks

The Pendulum

The mood swings of the securities markets resemble the movement of a pendulum. Although the midpoint best describes the ...

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📌⚖️ Ray Dalio

Five-Step Process

Use the 5-Step Process to get what you want: 1) Set clear goals, 2) Identify problems, 3) Diagnose root causes, 4) Desig...

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🎯📖 John Templeton

Patience and Perseverance

The only investors who shouldn't diversify are those who are right 100% of the time. For the rest of us, patience and di...

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👔📖 Philip Fisher

Management Integrity

Does the management have unquestionable integrity? Management that misleads shareholders will eventually mislead investo...

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🔮📖 Seth Klarman

Complex Situations

We seek opportunity in complexity - spinoffs, restructurings, bankruptcies. Where others see chaos, we see potential val...

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🏦📖 John Bogle

Asset Allocation

Your asset allocation - the mix of stocks, bonds, and cash - is the most important investment decision you'll make.

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📌🎩 Warren Buffett

Approximately Right

It is better to be approximately right than precisely wrong.

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📈🧠 Charlie Munger

Power of Compounding

Understanding both the power of compound interest and the difficulty of getting it is the heart and soul of understandin...

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📌📈 Peter Lynch

Turnarounds

Turnarounds are companies that have been battered and depressed, and have the potential to recover.

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