Personal Investment Philosophy — Write Your Own Rules

Learning Objectives

After reading this chapter, you will be able to:

• Apply: Philosophy = compass; strategy = execution path
• Explain how fit temperament + horizon + competence + risk + goals
• Apply: Written buy/sell rules, allocation, journal = professional investing
• Explain how philosophy evolves; core principles stable

Introduction

Ask ten great investors "How to invest?" — you get ten different answers: Value, Growth, Index, Quant...

The right approach: choose what matches your temperament, knowledge, and goals.

Copying is easy; conviction cannot be borrowed.

Core Concepts

Financial Terms

Investment Decision

Personal Constitution (Example)

• No investing in FOMO
• Leverage avoid
• Diversification maintain
• Quality businesses only
• Patience — process over emotion

Ultimate One-Line Philosophy

Great management + strong moat + fair price + long hold

Manifesto Checklist

✅ Understood businesses only ✅ Quality first ✅ Margin of safety ✅ Long-term thinking ✅ Diversification ✅ Process, not emotion

Key question: "Will my philosophy keep me disciplined even in difficult times?"

"Conviction cannot be borrowed."

Formula & Explanation

Philosophy Fit Test

Sample Buy Rules (Quantitative Filter)

Barbell Allocation

Philosophy vs Strategy

Visual Guide

Worked Example — Indian Market

Example 1 - Journal Entry

Stock | Date | Thesis | Buy Price | Invalidation trigger | Review date.

Example 2 - Philosophy Line

One sentence filter: what you buy, at what price, for how long.

Real World Example

Investor A copied a social media strategy. When the market fell, he panicked — because the strategy was not his own.

Investor B wrote a personal philosophy: what to buy, why, and when to sell. When the market fell, he stayed calm.

Ten years later: Investor B was successful.

Strategy works only when you believe in it.

Case Study

Philosophy-driven investor example:

Rules: Quality businesses, ROCE > 20%, debt-light, 10-year horizon, IT sector competence.

Universe: TCS, Infosys (understood), HDFC Bank (banking competence) — not random mid-cap tips.

Sell rule: Thesis break (margin collapse, governance) — not daily price noise.

Contrast: FOMO buyer jumps into Coal India cyclical peak without philosophy → wrong sector, wrong time.

CFA Exam Tip

A senior CFA analyst treats philosophy as an operating system:

5 Pillars:

1. Temperament — Can you tolerate a 50% drawdown? Or panic at 10%?
2. Time Horizon — Short (1–3Y), Medium (3–5Y), Long (10+Y)
3. Circle of Competence — IT, Banking, FMCG?
4. Risk Tolerance — Financial capacity ≠ emotional capacity
5. Goals — Retirement, freedom, education, wealth

7-Step Build Process:

1. Self-identify (aggressive/conservative/analytical/patient)
2. Write rules
3. Buy rules (ROCE, D/E, FCF)
4. Sell rules (thesis break, governance, extreme valuation)
5. Asset allocation (e.g. 70/20/10)
6. Review process (quarterly results, annual portfolio — not daily noise)
7. Investment journal

Evolution path: Speculation → Trading → Value → Quality Investing (core principles stable)

Ray Dalio: "Principles are ways of successfully dealing with reality."

Common Mistakes

• Copying others' strategy without a fit test
• Changing philosophy every bull market
• No written rules
• Ignoring risk (leverage, concentration)
• Reacting to short-term noise
• Chasing stock tips without building a philosophy

Key Takeaways

• Philosophy = compass; strategy = execution path
• Fit temperament + horizon + competence + risk + goals
• Written buy/sell rules, allocation, journal = professional investing
• Philosophy evolves; core principles stable
• Success starts with knowledge, ends with discipline

"In investing, success begins with knowledge and ends with discipline."

Disclaimer: Sample rules are illustrative; not personal financial advice.

Practice Questions

Chapter: Personal Investment Philosophy | Part 09 | Try before reading answers.

Q1 (Conceptual): Personal Investment Philosophy — what is the core message of this chapter in one sentence?

Q2 (Calculate): Apply formula: Strategy Fit = f(Temperament, Time Horizon, Competence, Risk Capacity, Goals) — use numbers from this chapter.

Q3 (Application): How do Investment Philosophy and Strategy interact in Personal Investment Philosophy decisions?

Q4 (Red Flag): Red flag: copying others' strategy without a fit test — why avoid relying on Personal Investment Philosophy alone?

Q5 (CFA Style): CFA-style trap when interpreting Personal Investment Philosophy?

Q6 (Decision): Personal Investment Philosophy looks strong but valuation stretched — invest, wait, or avoid?

Q7 (Lab): Complete one Personal Investment Philosophy exercise in Part 09 Practice Lab.

Answer Key

Go deeper: Part 09 Practice Lab

FAQ {#faq}

Q: Personal Investment Philosophy — what is the second check when evaluating this concept?

A: Changing philosophy every bull market

Q: How do you connect theory with Indian market practice for Personal Investment Philosophy?

A: Pull the same metric's 3-year trend from Screener/Trendlyne plus the company annual report — a paper formula alone is not sufficient.

Q: personal-investment-philosophy — why should you avoid this mistake?

A: Copying others' strategy without a fit test

Q: personal-investment-philosophy — no written rules red flag — why avoid it?

A: No written rules

Q: How do I drill this chapter's concepts in the Practice Lab?

A: Open Part 09 Practice Lab → use the FAQ Drill row for personal-investment-philosophy; verify answers in the Chapter FAQ Quick Index.

Practice Lab FAQ: Full part FAQ index — Part 09 Practice Lab

Related Topics

• Previous Chapter: 68-Great Investors Wisdom
• Next Chapter: 70-Final Blueprint
• Part Overview: Part 09 Investor Operating System
• Book Index: Full Table of Contents

Disclaimer: Educational content only. Not investment advice. Consult a qualified financial advisor before investing.