The best environment for altcoins is a slow, upward move following Bitcoin. As we’ve seen in recent days, other altcoins like Ether and Cardano have started to show strength. If Bitcoin remains to move to the upside, more altcoins can see upward breakouts.
Or it could be the other way around?
We might be possibly seeing an altcoin season as most of the altcoins are increasing. Altcoin's rally will surely give a chain reaction to Bitcoin's price.
Cardano is one of the most noticeable alt that showed strength after they have announced the launch date on their upragde named "Shelley".
https://dailyhodl.com/2020/06/05/cardano-becomes-top-10-cryptocurrency-as-shelley-launch-approaches/ While, Eth is keeping the upward pace, and Tether gradual increase of capitalization overtakes XRP in the third spot in CMC.