BTCD

BTC.D measures Bitcoin's proportional share of the total cryptocurrency market capitalization, expressed as a percentage. The index is calculated by dividing Bitcoin's market cap by the aggregate market cap of the top 125 crypto assets, with constituent weights updated daily. On Paragon (HIP-3), the BTC.D perpetual is priced via Pyth Network oracle feeds with sub-second updates, falling back to a weighted median across eight exchanges (Binance, OKX, Bybit, Kraken, Kucoin, Gate IO, MEXC, and Hyperliquid) when Pyth is unavailable. The index trades 24/7/365 and is used by traders to gauge Bitcoin's relative strength against altcoins — a rising BTC.D suggests capital rotation into Bitcoin, while a falling BTC.D signals altcoin season and risk-on behavior within the crypto market.