That was a momentary situation coins can vary in there dip at various time that doesn't mean bitcoin is less stable than the above altcoins you mentioned besides bitcoin experiences the most volatility
it could be like that, maybe this is a tough year for bitcoin. but my belief is still the same, bitcoin will experience good value again. so does altcoin. all will experience fluctuations
Bitcoin affects the value of other coins and usually the first one changes so that Bitcoin always looks up and down, while Altcoin has a longer change because it is influenced by Bitcoin because sometimes sometimes before altcoin goes up or down, Bitcoin has undergone some changes and it makes Bitcoin look more unstable.