The Bitcoin dominance chart will offer us clues to Alt-Season
Dominance topped out at 2019s high of $73, making it a strong resistance
Since the beginning of the year, altcoins have been injected with liquidity from Bitcoins momentum.
We can look out for Fibonacci's key 0.618 level at $64. When this level was broken and held at the end of June 2020, it triggered an altcoin rally across the board - Ada, Eth, Link, Waves, etc.
Good luck!