A share priced at ₹80 is not cheaper than one priced at ₹4,000. Price alone tells you nothing about a company’s size — it depends entirely on how many shares exist. Market capitalisation is the number that fixes this confusion, and it underpins how funds, indices and SEBI categories are all defined.
What is Market Capitalisation?
Market capitalisation — market cap — is the total market value of a company’s outstanding shares.
Market Cap = Share Price × Total Number of Outstanding Shares
It answers a simple question: what would it cost to buy every share of this company at today’s price?
Why Share Price Alone Is Meaningless
| Company A | Company B | |
|---|---|---|
| Share price | ₹80 | ₹4,000 |
| Shares outstanding | 500 crore | 2 crore |
| Market cap | ₹40,000 crore | ₹8,000 crore |
Company A’s shares cost a fiftieth of Company B’s, yet Company A is five times larger. The ₹80 share is not “cheap” and the ₹4,000 share is not “expensive” — those words only mean something relative to earnings or assets, which is what ratios like P/E and P/B measure.
This is also why a stock split changes nothing fundamental. Splitting one ₹4,000 share into ten ₹400 shares doubles nothing — market cap is identical before and after.
Total vs Free-Float Market Cap
| Total Market Cap | Free-Float Market Cap | |
|---|---|---|
| Counts | All outstanding shares | Only publicly tradable shares |
| Excludes | Nothing | Promoter, government and locked-in holdings |
| Used for | SEBI’s large/mid/small cap classification | Index weighting — Nifty, Sensex |
A company with ₹1,00,000 crore total market cap but 75% promoter holding has only ₹25,000 crore of free float. It counts as very large for SEBI categorisation, but carries far less weight in the Nifty than its headline size suggests.
SEBI’s Large, Mid and Small Cap Classification
This is the definition that drives mutual fund categories, and it is rank-based rather than value-based.
| Classification | SEBI definition | Characteristics |
|---|---|---|
| Large Cap | Companies ranked 1–100 by market cap | Established, liquid, lower volatility |
| Mid Cap | Companies ranked 101–250 | Growing, higher volatility, more room to expand |
| Small Cap | Companies ranked 251 onwards | Highest growth potential and highest risk, thin liquidity |
AMFI publishes this list twice a year using average market cap over the previous six months. Because it is rank-based, the rupee threshold for each bucket moves as the market moves — in a strong bull market, the cutoff to remain in the top 100 rises.
This classification directly determines what a large cap, mid cap or small cap fund is permitted to hold.
What Market Cap Tells You
| Segment | Typical traits | Suits |
|---|---|---|
| Large cap | Stable earnings, well-researched, easy to buy and sell | Core holdings, shorter horizons |
| Mid cap | Faster growth, more volatile, less analyst coverage | 7+ year horizons |
| Small cap | Highest potential and deepest drawdowns, thin trading | 10+ year horizons, high risk tolerance |
What Market Cap Does Not Tell You
This is where market cap gets over-used. It measures size — nothing more.
- It ignores debt entirely. Two companies with identical ₹50,000 crore market caps are very different if one carries ₹40,000 crore of debt and the other none. Enterprise Value — market cap plus debt minus cash — is the measure that accounts for this.
- It says nothing about valuation. A large market cap does not mean a stock is expensive; that requires comparing price against earnings, assets or cash flow.
- It says nothing about quality. Size and business quality are unrelated. Large companies can have poor returns on capital; small ones can be excellent businesses.
- It reflects sentiment, not just fundamentals. Market cap is price-driven, and price moves on expectations. A company’s market cap can halve in a quarter with no change to the underlying business.
Market Cap vs Enterprise Value
Enterprise Value = Market Cap + Total Debt − Cash
Enterprise Value represents what it would truly cost to acquire a business — you take on its debt and gain its cash. For comparing companies with very different debt levels, EV-based measures are more informative than market cap alone. Pair this with the debt-to-equity ratio to see the leverage picture.
Key Takeaways
- Market Cap = Share Price × Outstanding Shares
- Share price alone says nothing about company size or whether a stock is cheap
- Free float excludes promoter and locked-in shares — used for index weighting
- SEBI classifies by rank: 1–100 large cap, 101–250 mid cap, 251+ small cap
- AMFI updates the classification twice a year
- Market cap ignores debt — use Enterprise Value when leverage differs
- Size is not quality and not valuation — market cap measures only size
- A stock split changes share price and share count but not market cap
Frequently Asked Questions (FAQ)
Q: What is market capitalisation in simple terms?
Market capitalisation is what the entire company is worth at today’s share price — calculated by multiplying the share price by the total number of shares. It is the standard way to compare company sizes, because share price alone depends on how many shares exist.
Q: What is the market cap formula?
Market Cap = Share Price × Total Number of Outstanding Shares. For example, a company with 20 crore shares trading at ₹500 has a market cap of ₹10,000 crore.
Q: How does SEBI classify large cap, mid cap and small cap?
By rank rather than by a fixed rupee value. Companies ranked 1st to 100th by market capitalisation are large cap, 101st to 250th are mid cap, and 251st onwards are small cap. AMFI publishes the list twice a year.
Q: What is free-float market capitalisation?
Free-float market cap counts only shares available for public trading, excluding promoter holdings, government stakes and other locked-in shares. Indices like the Nifty 50 and Sensex use free float for weighting, so a heavily promoter-owned company carries less index weight than its total size implies.
Q: Does a higher market cap mean a better company?
No. Market cap measures size only. It says nothing about profitability, debt levels, growth or management quality. Large companies can be poorly run and small ones can be excellent businesses — size and quality are separate questions.
Q: What is the difference between market cap and enterprise value?
Market cap counts only the equity value. Enterprise Value adds debt and subtracts cash, representing what it would actually cost to acquire the business. When comparing companies with very different debt levels, enterprise value is the more meaningful measure.
Q: Does market cap change when a stock splits?
No. A split increases the share count and reduces the price proportionally, leaving market cap unchanged. Splitting one ₹1,000 share into ten ₹100 shares changes nothing about what the company is worth.
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