Yes Read about Bitcoin Dominance Cycle.
If Bitcoin Dominance increases, Bitcoin prices increases, and altcoins prices decrease or are stable - that's what happens when people move volumes from altcoins to buy more Bitcoin.
Remember Crypto generate value from demand and supply(volumes/market activity)
Therefore altcoin prices decrease or tend to be stable when people move all volumes to BTC and leave Altcoins with low volumes to support price increase.#BTCBreak71K #TrumpInPump