Fundamental analysis · Beginner

Market Capitalization Explained

Market cap prices the residual claim on a company. Enterprise value prices the company, and the gap between them is the debt.

Last reviewed 15 September 2026 by the MarketPro research desk · Editorial policy

In short

Market capitalisation is the share price multiplied by shares outstanding, giving the market's current price for a company's entire equity. It excludes debt, so enterprise value, market cap plus net debt minus cash, is the better measure of what buying the whole business would cost. Free float, the portion of shares actually available to trade, determines liquidity and can differ hugely between companies of the same market cap.

What to remember

Market cap ignores debt. A six-fold gap on market cap can be a three-fold gap on enterprise value once net debt is added.
A £10bn company with a 15% free float has £1.5bn of tradable stock, which is what sets the spread and the slippage.
The size label is circular. A 60% fall reclassifies a company, forcing index selling that has nothing to do with the business.
Market cap is a price for future profit, not a measure of present scale. Larger revenue and more employees can mean a smaller market cap.

Lesson 14 of 24 in Fundamental analysis

PreviousDividend Yield and Payout Ratio NextSector and Industry Analysis

Market capitalisation is the share price multiplied by the number of shares outstanding. It is the market's current price for owning the whole equity of a company. It is not what the company is worth, it is not what an acquirer would pay, and it has no direct relationship to revenue or profit, all of which makes it more useful as a risk label than as a valuation.

Two companies, the same revenue, a six-fold gap

Company A books £2bn of revenue and trades at a £3bn market cap. Company B books the same £2bn and trades at £18bn. Nothing is wrong with either number. The market is pricing expectations, and it expects B's revenue to grow and A's to stagnate or decline.

Now add the balance sheets. A carries £2.5bn of net debt. B holds £1bn of net cash. The price of buying the whole business is enterprise value, which is market cap plus net debt:

	Company A	Company B
Market cap	£3.0bn	£18.0bn
Net debt	£2.5bn	(£1.0bn)
Enterprise value	£5.5bn	£17.0bn
EV / revenue	2.75x	8.5x

On market cap the gap was six-fold. On enterprise value it is three-fold. Adding the debt back halved it, and the equity price hides that debt because lenders are paid before shareholders and market cap only prices what is left over. For any company carrying meaningful debt, enterprise value is the number that describes the price of the business rather than the price of the residual claim on it.

The ratios in the last row are worth a second look too. EV to revenue of 2.75x against 8.5x is the market saying it expects B to convert revenue into profit at a far higher rate, or to grow it far faster, or both. That is a testable claim. Pull the operating margin and the three-year revenue growth rate for each and you can see whether the premium is being paid for something that already exists in the accounts or for something that has been promised. Most of the work in valuation is turning a multiple back into the assumption it encodes.

Free float: the shares that actually trade

Shares outstanding includes stock that never trades. Founder holdings, government stakes, cross-shareholdings and locked-up employee stock all count towards market cap and none of them are available to buy.

A company with a £10bn market cap and a 15% free float has £1.5bn of tradable stock. That is the number that determines whether a large order moves the price, how wide the spread is, and how violently the shares react to an index rebalance. Two companies with identical market caps can have completely different liquidity, and the difference is not visible in the headline figure.

9 more sections in MarketPro

What actually changes as size changes

Spread and slippage. A large-cap may quote a spread of a few basis points. A small-cap can quote 1% or more, which is a cost you pay on entry and again on exit before the position has done anything.
Index membership. Crossing a size threshold forces index funds to buy, and dropping below forces them to sell, in both cases regardless of the business.
Analyst coverage. Large-caps are covered by dozens of analysts, small-caps sometimes by none. Less coverage means more mispricing, in both directions.
Volatility. Smaller companies typically show larger daily ranges, which is a position-sizing input rather than a quality judgement. The position size calculator is where that gets handled.

Where the label misleads

Market cap changes when the share price changes, which means the classification is circular. A company that falls 60% becomes a mid-cap, and index rules then force selling by funds mandated to hold large-caps only, which pushes the price down further. That mechanism has nothing to do with the business and everything to do with the label.

It is also not comparable across markets. A large-cap on a smaller national exchange can be a mid-cap by US standards, so a fund described as large-cap may hold companies a US investor would consider mid-sized. Thresholds are conventions, they differ by provider, and they are redrawn as markets grow.

The most common misreading is treating market cap as a measure of size in the ordinary sense. A company with 200,000 employees and £40bn of revenue can be worth less than a company with 3,000 employees and £2bn of revenue, because the market is pricing future profit rather than present scale. Market cap is a price, and a price is an opinion.

Using size as a risk setting

The practical use is in position sizing and expectations rather than in selection. For a small-cap, assume a wider spread, assume the position takes longer to exit at a reasonable price, and assume a larger daily range. Those three assumptions change what a sensible position size is, and getting them wrong is a more common source of loss than picking the wrong company.

The same logic runs through other markets. Currency majors trade with tight spreads and deep books; exotic pairs do not, and the difference is the same liquidity difference wearing different clothes. Size, in every market, is mostly a statement about how expensive it is to change your mind.

Finish this lesson in MarketPro

The rest of Market Capitalization Explained, a quiz that checks it landed, and your place kept in the curriculum.

9 more sections of this lesson
All 320 lessons, with no cap and no paywall
Free on any account, including a free one

In your browserContinue on webor continue on web

Same account as the app · No install · Free to start

Or scan with your phone camera to get the MarketPro app.

Download on theApp Store Get it onGoogle Play

Free account, no card needed.

Not investment advice. Past performance is not indicative of future results.

Run the numbers while this is fresh

Work it through on your own position size. Nothing leaves your browser and there is no sign-up: Position size calculator.

Written and reviewed by the MarketPro research desk

MarketPro is a trading-signal and trading-education app operated by Harajuku Holdings LTD (Cyprus). Our signal desk publishes and tracks every trade idea in-app, and every page here is checked against the app's live behaviour before publishing. Last reviewed 15 September 2026. How we produce signals and content · About MarketPro

FAQ

Market Capitalization Explained: questions

What is the difference between market cap and enterprise value?

Market cap is share price times shares outstanding, so it prices only the equity. Enterprise value adds net debt and subtracts cash, giving the cost of acquiring the whole business including its obligations. For a debt-free company holding cash the two are close. For a leveraged company enterprise value can be several times market cap, which is why acquirers and credit analysts use it in preference.

Does a larger market cap mean a safer investment?

Larger companies tend to be more diversified, better covered by analysts and more liquid, which usually means smaller daily ranges and cheaper execution. That is a tendency and not a protection. Large companies have lost the majority of their value, and index membership can force selling that accelerates a decline. Size changes the character of the risk rather than removing it.

Why does free float matter more than shares outstanding?

Because shares held by founders, governments or in locked-up employee plans count towards market cap but cannot be bought. The free float is what actually trades, so it determines the bid-ask spread, how far a large order moves the price and how sharply the stock reacts to index changes. Two companies with identical market caps can have completely different trading characteristics as a result.

Trade · Learn · Earn

The whole academy is free in MarketPro

All 320 lessons, 12 guided paths, quizzes and a daily streak. Free on every account, in the app or your browser, with vetted free signals alongside it.

In your browserContinue on webor continue on web Download on theApp Store Get it onGoogle Play

Same account as the app · No install · Free to start

Not investment advice. Past performance is not indicative of future results.