Market Cap

Market capitalization (market cap) is calculated by multiplying Bitcoin's current price by the total number of coins in circulation. For example, if Bitcoin trades at $100,000 and there are 19.8 million BTC in circulation, the market cap is approximately $1.98 trillion. This metric provides a way to compare Bitcoin's total value against other assets like gold ($15+ trillion), the S&P 500 ($45+ trillion), or global real estate ($300+ trillion).

While market cap is useful for rough comparisons, it has limitations specific to Bitcoin. Not all coins in circulation are actually available — an estimated 3-4 million BTC are permanently lost (owner lost keys, Satoshi's coins, etc.), and a significant portion is held in long-term cold storage and unlikely to be sold at current prices. This is why "realized cap" (which values each coin at the price it last moved on-chain) is often considered a more accurate measure of the capital actually invested in Bitcoin.

Market cap also suffers from the "last price" problem. If someone buys 0.01 BTC at $200,000, the market cap calculation applies that price to all 19.8 million coins — even though the vast majority were acquired at much lower prices and the market could not absorb the sale of all coins at the current price. Despite these limitations, market cap remains the standard metric for comparing Bitcoin's size relative to other asset classes and tracking its growth over time.