Over the years I have noticed that most alt season started as follows:
1. $BTC pumps first.
2. $ETH $BET & $LTC coin pumps next, leading indicators of the Alt season.
3. Big marketcap tokens next. Usually top 20 on CMC.
4. Then full blown Alt season.
You were mentioned, what is happening in the Cryptocurrency history. You should know that altcoins always provided the biggest rewards in the average market like last year.