What Is Market Capitalisation? (Market Cap Explained)
Market capitalisation — "market cap" — is the total market value of a company's outstanding shares. It is the single most useful measure of a company's size, far more so than its share price on its own.
How market cap is calculated
Market cap = current share price × total number of outstanding shares. A company whose shares trade at ₹500 with 10 crore shares outstanding has a market cap of ₹5,000 crore. Because it multiplies by the share count, a ₹50 stock can be worth far more than a ₹5,000 stock — the price per share alone tells you nothing about size.
Large cap, mid cap, small cap
In India, SEBI defines the market-cap tiers by rank: the top 100 companies by market cap are large caps, the next 150 (ranks 101–250) are mid caps, and everything from rank 251 onwards is small cap. Large caps are generally more stable and liquid; small caps can grow faster but carry more risk and trade thinly.
Why it matters
- It lets you compare companies of very different share prices on a like-for-like basis.
- Index inclusion (NIFTY 50, SENSEX) is driven largely by market cap and free float.
- Mutual-fund mandates (large-cap fund, small-cap fund) are defined by these tiers.
See it in the data
Every company's live market cap, and its rank in the market, is shown on its stock page and the market-cap leaderboard. Developers can read the market_cap field via the API or filter the universe by size with the screener.