Free Float and Shares Outstanding

Shares outstanding is simply the total number of shares a company has issued and not repurchased — the number you multiply by the share price to get market capitalization. Free float is a smaller number: the shares that are actually available for public investors to buy and sell, excluding stakes held by founders, governments, other corporations, or anyone locked in by regulation or a long-term strategic commitment who won't be selling into the market anytime soon.

The gap between the two can be enormous. A company can have a $50 billion market cap on paper, but if the founding family controls 70% of shares outstanding and never trades, the free float is closer to $15 billion — and that smaller number is what actually determines how easily the stock can be bought or sold without moving the price.

This distinction matters most in index construction. Major indices like the S&P 500 and MSCI World weight companies by free-float market cap, not total market cap, precisely because an index fund needs to be able to actually buy the shares it's tracking. A company with a huge total market cap but a tiny free float would force an index fund to try to buy shares that essentially never trade, driving up the price artificially. Free-float weighting keeps index constituents proportional to what's realistically investable.

For a trader, low free float relative to total shares outstanding is also a warning sign for liquidity risk and price manipulation susceptibility — a stock can look big by market cap while trading paper-thin, with any large order capable of moving the price sharply.