Market Capitalization

Market capitalization (or "market cap") is the spot price of an asset multiplied by the number of units in circulation. For Bitcoin: BTC/USD price × circulating supply (currently ~20 million BTC).

The number is useful as a rough gauge of an asset's scale, especially for comparison: at any given time, BTC's market cap can be compared to gold's ($15-20T as of 2026), Apple's market cap ($3.5T), or the entire S&P 500's total value ($50T).

What market cap is not:

• It's not "the amount of money that has flowed into Bitcoin." That figure - sometimes called realized cap - is much smaller, because most BTC has been held through long-stretches of price appreciation without changing hands.
• It's not "the amount you'd get if you sold all the Bitcoin." Selling 20M BTC at once would crater the price; the actual liquid market depth at any given price level is a tiny fraction of total supply.
• It's not strictly comparable between Bitcoin and "cryptos" in general. Many altcoins have huge insider allocations, opaque circulating supplies, or near-zero liquidity. Their "market cap" is often a fictional number used in marketing.

More informative alternatives Bitcoiners sometimes cite:

• Realized cap - sum of every UTXO valued at the price it was last moved. A truer measure of cost basis in aggregate.
• MVRV ratio (market value / realized value) - how stretched current price is vs realized cap.
• Volume-adjusted metrics - actual trading volume, on-chain transaction value, etc.

For headline use, market cap is fine. For analysis, look deeper. Bitcoin's price tells you what the last marginal buyer paid; the market cap is that number multiplied by every BTC anyone holds, whether or not they're selling.