Bitcoin dominance is the percentage of the entire cryptocurrency market cap that Bitcoin alone accounts for. Think of it as a barometer measuring where conviction sits in the market at any given moment. When Bitcoin dominance climbs, it usually means investors are pulling money out of smaller, riskier tokens and parking it in BTC - a flight to relative safety. When dominance falls sharply, it typically signals that traders are comfortable taking risk again and capital is flowing into altcoins hunting for bigger gains. Watching dominance shift alongside total market cap gives traders a cleaner picture of what phase the market is in.