2.1.2 Market Capitalisation

What the number means

Market capitalisation is calculated by multiplying a company's share price by the total number of shares outstanding. A company with 10 crore shares trading at ₹500 each has a market cap of ₹5,000 crore. This single figure is used to sort companies into large cap, mid cap and small cap buckets, each with a different risk and return profile.

These buckets are defined by SEBI, not by marketing convention. The top 100 companies by market cap are large cap, the next 150 (ranks 101-250) are mid cap, and everything from 251 down is small cap. The classification carries real constraints: a large-cap fund must hold at least 80% of its equity in the top 100, a mid-cap fund in ranks 101-250, and a small-cap fund in companies ranked 251 and below. Because market cap moves with price daily, a company near a boundary can shift categories, occasionally forcing funds to adjust holdings to stay compliant.

Why size correlates with risk

Large cap companies are typically established, profitable and heavily covered by analysts, which tends to make their share prices less volatile. Small cap companies are often younger or less proven, with less analyst coverage and lower trading volumes, which usually means bigger price swings in both directions. Mid caps sit between the two.

India's history broadly supports the size-risk relationship. The Nifty Smallcap 250 has beaten the Nifty 50 over most fifteen-year rolling periods, but with far deeper drawdowns and slower recoveries. In the 2018 correction many small caps fell 50-70% and took two to three years to recover, while the Nifty 50 fell around 15% and recovered within months. For an investor with a genuine fifteen-year horizon and the temperament to hold through such falls, small caps can add real return; for one who checks weekly and panics at a 40% drop, they are a source of genuine harm.

No segment is automatically better

Higher growth potential in small caps comes bundled with higher risk of permanent loss, and the safety of large caps comes bundled with typically slower growth. Most diversified portfolios hold a mix, weighted by how much volatility the investor can genuinely tolerate rather than by which segment had the best recent run.

A common structure is a core allocation in large caps for stability with satellite allocations in mid and small caps for growth. There is no universally correct ratio, but a useful principle is that money needed within seven years should lean heavily toward large caps, while money with a fifteen-year-plus horizon can tolerate a more aggressive tilt toward smaller companies whose extra volatility has time to resolve.