Bitcoin Dominance (BTCD) is a metric that measures Bitcoin's market capitalization as a percentage of the total cryptocurrency market capitalization. It is calculated by dividing Bitcoin's market cap by the combined market cap of all cryptocurrencies. When Bitcoin Dominance rises, it typically indicates capital flowing out of altcoins and into Bitcoin; when it falls, it suggests an 'altcoin season' where alternative cryptocurrencies are outperforming. Traders use this metric to inform portfolio allocation decisions between Bitcoin and altcoins.
Example
“Bitcoin Dominance climbed from 42% to 55% over three months, signaling that traders were rotating out of altcoins and into BTC as a risk-off move.”