I do not know why this happens, but the altcoins fell after bitcoin. I hope that over time this dependence will not be so strong and the altcoins will not depend on bitcoin.
And this is because when bitkoyn starts to fall, everyone starts fixing in it, and so its capitalization grows. Once bitkoyn grows, most of the investment flows into the altokkony, and their price grows accordingly.
Now bitcoin is growing, and all the violas are going down. Therefore, this is not an indicator. Alts do not depend on bitcoin, but on very rich people.