Chapter 1: The Basics
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Day 9: Market Capitalisation — How Big Is Big?
From small caps to large caps — size actually matters here
2 min read
📖 The School Size Analogy
A primary school in a small town. A large secondary school in a big city. And a university. All of them are "educational institutions." But they're wildly different in size, stability, and potential.
Market capitalisation classifies companies the same way. Small, medium, large. Each comes with different risk, different return potential, and different behaviour in market downturns.
Understanding this classification is your entry ticket to intelligent portfolio construction. 🎓
A primary school in a small town. A large secondary school in a big city. And a university. All of them are "educational institutions." But they're wildly different in size, stability, and potential.
Market capitalisation classifies companies the same way. Small, medium, large. Each comes with different risk, different return potential, and different behaviour in market downturns.
Understanding this classification is your entry ticket to intelligent portfolio construction. 🎓
The Formula
Market Capitalisation = Current Share Price × Total Number of Shares
Example: Reliance Industries
Share Price = ₹2,800
Total Shares = 675 crore
Market Cap = ₹2,800 × 675 crore = ₹18,90,000 crore (~₹19 lakh crore!)
That's roughly $230 billion USD. India's most valuable company.
Example: Reliance Industries
Share Price = ₹2,800
Total Shares = 675 crore
Market Cap = ₹2,800 × 675 crore = ₹18,90,000 crore (~₹19 lakh crore!)
That's roughly $230 billion USD. India's most valuable company.
The Three Tiers
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Large CapTop 100 companies by market cap. ₹20,000 crore+. Think TCS, Infosys, HDFC Bank, Reliance. Stable, liquid, less volatile. Lower returns but you sleep at night.
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Mid CapRank 101–250. ₹5,000–₹20,000 crore. Growing companies with more upside than large caps but more risk. The sweet spot for many investors.
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Small CapRank 251+. Below ₹5,000 crore. High volatility, low liquidity. Can multiply 5x or fall 70%. Only for patient, risk-tolerant investors. NOT for beginners.
Free Float Market Cap
Free Float = Only the shares actually available for public trading
If a promoter holds 60% of shares, those aren't easily available in the market. So the "free float" is only 40%.
SENSEX and NIFTY use free float market cap — not total market cap — to decide which stocks get more weightage in the index. This is why Reliance has massive weight in NIFTY even though there are companies with higher total market cap.
If a promoter holds 60% of shares, those aren't easily available in the market. So the "free float" is only 40%.
SENSEX and NIFTY use free float market cap — not total market cap — to decide which stocks get more weightage in the index. This is why Reliance has massive weight in NIFTY even though there are companies with higher total market cap.
| Company Type | Risk Level | Typical Returns (10yr) | Best For |
|---|---|---|---|
| Large Cap | Low-Medium | 11–14% CAGR | Core portfolio, beginners |
| Mid Cap | Medium-High | 14–18% CAGR | Growth-oriented investors |
| Small Cap | Very High | 15–25% or negative! | Experienced investors only |
🎯 Today's Takeaway:
Market Cap = Share Price × Total Shares. Large cap (top 100) = stable, liquid, lower returns. Mid cap (101–250) = growth potential, moderate risk. Small cap (251+) = high risk, high reward. Start with large caps and index funds. Tomorrow: The mechanics of how stocks go up and down in detail!
Market Cap = Share Price × Total Shares. Large cap (top 100) = stable, liquid, lower returns. Mid cap (101–250) = growth potential, moderate risk. Small cap (251+) = high risk, high reward. Start with large caps and index funds. Tomorrow: The mechanics of how stocks go up and down in detail!