I'm not really an expert on this subject, but what happened in Q4 2017, with now is a very different matter. Currently, the adoption of bitcoin is very much, moreover there are so many new regulations that support the development of bitcoin. So, I feel that the current price is much stronger than in 2017. It is also proven that this year, the bitcoin price has crossed its ATH 2x.

in the case of altcoins, we still don't know whether there will be a massive increase or not. however, various predictions and speculations argue that, it is possible that altcoin prices will tend to increase massively, but the time is still undetermined. it can happen at any time. it is also sometimes supported by rising bitcoin prices. you can see in the previous altcoin increases, most starting from the pump price of bitcoin.