Use market cap as a comparative measure without mistaking it for money invested or available liquidity. The checks below separate measured market facts from forecasts and personal decisions.
- Market cap is price multiplied by supply.
- It is not a pool of invested cash.
- Liquidity and supply activity provide essential context.
The calculation
Market capitalization multiplies a reference price by circulating supply. Because the price comes from marginal trades, market cap can change by billions without billions of fresh cash entering or leaving.
Lost and illiquid supply
Some coins may be lost, dormant or held off-market. Standard market cap usually counts them because ownership status is unknowable from inactivity alone, limiting what the metric says about tradable supply.
Name the market and the timestamp. A BTC/USD trade, a BTC/USDT quote, and a multi-venue reference are related observations, not interchangeable prices.
Pair it with liquidity
Order-book depth, realized capitalization, volume quality and holder distribution answer different questions. No single number captures network value, liquidity and investment risk.
The calculation and its inputs
Market capitalisation is the price of one coin multiplied by the number of coins issued. Both inputs need a source. The price is a reference rate from selected exchanges at a moment in time, so two sites can differ slightly.
The supply is derived from the block subsidy schedule and is precise, but it includes every coin ever issued — including the millions believed lost — so 'circulating supply' figures vary by method. Bitcoin's market cap has ranked with the largest companies and, at times, with gold's total value, which is the comparison usually being made when the figure is quoted.
What it does not mean
It is not the money that has been invested in bitcoin. It values every coin at the price of the last one traded; the total that actually flowed in is far smaller, and selling even a fraction of the supply would move the price well below the figure.
It is not what you would receive by selling all of it, and it says nothing about liquidity or about how concentrated ownership is. Comparisons with a company's market cap are loose too: a company's value reflects earnings, a monetary asset's reflects what people believe about its future demand.
Better measures for some questions
Realised capitalisation values each coin at the price when it last moved on-chain. It rises only when coins change hands, filters out lost coins, and approximates the capital that actually entered the network; the ratio of market cap to realised cap has been used to gauge how far the market sits from its holders' cost basis. Trading volume and order-book depth answer liquidity questions.
On-chain distribution data answer concentration questions. Each measure has its own caveats, and the methodology page on this site explains which figures it publishes and why.
Check the market claim before acting
Write down the pair, venue, timestamp, spread, and source behind a number. A historical pattern or current reference is evidence about a market observation, not a promise about the next price.
Common questions
How is Bitcoin's market cap calculated?
Price multiplied by the number of coins issued. Both inputs need a source: the price is a reference rate from selected venues and the supply comes from the block subsidy schedule, so two sites can differ slightly.
Does market cap equal the money invested in Bitcoin?
No. It values every coin at the latest marginal price, including coins that have not moved for years. Far less money has flowed in than the market cap suggests, and selling a large amount would move the price well below the figure.
What is realized cap?
A measure that values each coin at the price when it last moved on-chain rather than at today's price. It grows only when coins change hands, which makes it a useful proxy for the capital that actually entered the network.
Sources and further reading
Primary documents this guide draws on. Links open the original publisher.
- Market capitalization U.S. Securities and Exchange Commission, Investor.gov
- Controlled supply Bitcoin Wiki
- Coinbase Bitcoin (CBBTCUSD) Federal Reserve Bank of St. Louis, FRED