The surge in altcoins has led many traders to forecast the dawn of a new altcoin season. According to "The Moon" a pseudonymous Twitter analyst, altcoin seasons follow a major run-up in the price of BTC, especially when the price stalls or pulls back.
It is absolutely optional that the altcoin season begins after the rise in the price of bitcoin. In 2017, the altcoin season began after the price of BTC declined and against this background, the price of altcoins began to increase not only against bitcoin, but also against the dollar.