Free Float

Imagine a large housing society with a thousand flats, but only two hundred of those flats are ever actually offered for sale or rent on the open market at any given time, the rest are owner-occupied and simply never come up for transaction. If you wanted to measure how liquid and tradeable that society's real estate genuinely is, counting all thousand flats would badly overstate the picture, only those two hundred genuinely reflect the active market. Free float does exactly this for a listed company's shares.

A company's total market capitalisation is simply its share price multiplied by all outstanding shares. Free float market capitalisation excludes shares that are not genuinely available for public trading, chiefly promoter holdings, government stakes in public sector companies, and any shares locked in under regulatory or contractual restrictions, counting only the shares that could realistically change hands in the open market at any time.

This distinction matters enormously for stock market indices. Nifty, Sensex and most major global indices weight companies by free float market capitalisation, not total market capitalisation, precisely because index weightings are meant to reflect how much of a company's value ordinary investors can actually buy and trade, not how much theoretical value exists on paper including shares that will essentially never be sold.

A company with a very high promoter shareholding, common among many Indian family-controlled businesses, can therefore have a large total market capitalisation but a comparatively modest free float, giving it less index weight, and often lower trading liquidity, than a similarly-valued company with a more widely dispersed shareholder base.

Whenever a company's index weight seems surprisingly small relative to its headline market capitalisation, low free float, driven by a concentrated promoter or government holding, is very often the explanation, a reminder that a company's total valuation and its actual tradeable liquidity are related but genuinely distinct numbers.