Bitcoin Dominance (BTC.D)
Percentage of Bitcoin market cap in total crypto market cap — measures alt season.
Bitcoin dominance (BTC.D) is an index showing what percentage of total crypto market capitalization belongs to Bitcoin.
Formula: BTC.D = BTC Market Cap / Total Crypto Market Cap × 100
Historical values:
•2017 pre-alt season: ~80%
•Alt season peak 2018: ~35%
•2020 DeFi summer: ~57%
•Alt season 2021: ~40%
•Bear market 2022: ~45-50%
How to use BTC.D:
•BTC.D rising: capital moving from alts to BTC → rotation back to "safety"
•BTC.D falling: capital spreading to alts → alt season beginning
•BTC.D below 40%: classic alt season signal
Tracking on TradingView: ticker BTC.D
Note: Growth of stablecoin count dilutes BTC.D without real alt season — track "altcoin season index" for cleaner signal.