WHY MY ALTCOINS LOSES VALUE EVERY TIME BTC MOVES ?

the cryptocurrencies world is a place of volatility,. everyone keeps talking about ETH could take BTC's position some day as possible but now we are in the moment when BTC is the king and future close too. when BTC goes up the value of altcoins go down , when the BTC goes down the value of altcoins stay in range or go down , however there are exceptions to that rule in a bloody market
Why happen that? let me explain you
BTC starts going up the whales sell their altcoins and stay in BTC and overvalue BTC, when this happen most people get into FOMO,,,
then whales sell their BTC in the store cheaper
maybe it can take an hour, a day , a week whenever.
pay attention to this stage:
BTC goes down the whales get into FIAT or USDT , when this happen many people sell and obtain gains ,
after the whales start to buy cheaper in their stores similar before, could take short or long term ,
example: the Bull in $20k a lot of whales got off the market to see the bear market till $7k , the mostly of them came back probably with a part of gains in $20k ..

so, would not you do the same?
THINK ABOUT IT,,,