Dominance (BTC.D) and Bitcoin ($BTC ) price impact altcoins (ALTS):
1. **BTC.D ↑ and BTC ↑:** ALTS ↓
2. **BTC.D ↑ and BTC ↓:** ALTS dump
3. **BTC.D ↑ and BTC stable:** ALTS stable
4. **BTC.D ↓ and BTC ↑:** ALTS pump
5. **BTC.D ↓ and BTC ↓:** ALTS stable
6. **BTC.D ↓ and BTC stable:** ALTS ↑
In essence, higher Bitcoin Dominance usually means lower altcoin prices, and vice versa.