How the large number appears
If the reference price rises by EUR 1,000 and the method multiplies roughly twenty million units, calculated market cap rises by roughly EUR 20 billion. The market did not need EUR 20 billion of fresh cash. The price applied to the entire multiplier changed.
The formula comes from equities, where share price times shares outstanding expresses the market value of equity. Bitcoin represents no claim on a company, profits or assets. Its market cap is a comparison metric, not a balance sheet.
The supply measure matters
One provider may use every issued BTC, while another removes provably unspendable or estimated illiquid units. Since lost keys cannot be known precisely, results can differ even at the same price.
When comparing Bitcoin with a company, gold or a currency, check what each figure represents. A common dollar unit does not confer common economic rights, risks or liquidity.
The whole market cap cannot be withdrawn
If every holder tried to sell, buyers would not wait at the last price for every unit. Sell orders would consume bids and move the price down. The same principle applies to shares and other traded assets.
A more useful execution question is how much depth exists within a price range and on which venues. Displayed depth is not a promise either: orders can be cancelled and the market changes during execution.
- market cap = price × selected supply
- cash inflow is not the change in market cap
- liquidating the whole supply would move price
What the metric is good for
Market cap helps track relative size or change under a consistent methodology. It does not reveal ownership distribution, daily volume, depth, leverage, custody safety or the prices individual holders paid.
A careful claim states the date, currency, price index and supply definition. Rather than saying the market put in a billion, say that a new marginal price raised the calculated multiple.