Yes, the altcoins price is really depends on the market movement of bitcoins once price of bitcoin fluctuate other coins will also follow.
There was a time in last year, when these two are used to be reciprocal of one another. But now, they seems to be directly proportional. I am not still sure that whether they are direct or indirect but whatever it is, things are quite good here in crypto. You can make healthy earnings from this. Altcoins are good too to make short term trading and earning on daily basis. Do try them.