If I think about the correlation between Bitcoin and Altcoins, you also know that between them both Bitcoin and Altcoins, the movements are sometimes compatible, or even opposite. An example occurred in mid-May this year, where the price of Bitcoin and Altcoin collapsed simultaneously, but their relationship was HTS, aka a relationship without status.
So overall, one can see Bitcoin as a less risky and more certain investment option. Meanwhile, most new altcoins are usually very risky, especially when their market cap is low. However, in most market situations, the price of Altcoins can be closely related to the price of Bitcoin. Altcoins often follow Bitcoin price movements with slight to large differences.