As I have observed most coins do have something in common with bitcoin. They would all drop when bitcoin drops as well. I have seen a few coin though that do not actually go with these movements. I see these coins better in a way that they have a different market than most do. These is essential because you will know that they are stable even when generally others are affected by current drop pulled by bitcoin. So in times when market is bad you don't have to worry about having to sell becuase bitcoin drops as a reference. I saw Dogecoin, USDT, BNB and many others to be like stand alone and like them aside from Ethereum.