The price of altcoins depends on demand in them.
But during the fall of the market the price of cryptocurrency falls and demand in altcoins falls too.
That is why it is important to check everything not to lose money during the fall of the market because such investments are very risky.
However, the movement of altcoins will greatly affect the bitcoin market without exception, but if the bitcoin market is relatively stable then altcoins will have the opportunity to increase based on the big news of each coin.