Every cryptocurrency is pegged to bitcoin. If for example, 1 coin is equal to 100 sats, then the value of bitcoin in usd increases, that 100 sats would be worth more now.
Agree, but sometimes here is some weird things.
Like look: bitcoin goes up - altcoins goes up, and then - it starts to flat - but altcoins dont, they go down. Dont know why, but it exists definitely
Well alts don't entirely rely on bitcoin's movement because they have their own markets with investore and traders as well. In general of course all of them are linked to btc but it doesn't mean that they're movements will always be influenced by bitcoin.