First am not a pro trader, but my trading techniques have proven fundamentals. I recycled around Bitcoin and some handful of good altcoins; I trade with a hand full of funds since altcoins and the bitcoin market move in the opposite direction; I fill my bags with altcoins when the alt markets are down against Bitcoin and sell them when the market is on the rise to buy bitcoin which will be on a downtrend at that moment.
This technique has worked for me over the years.
How on the Green Earth that worked man?
The scenario in 2020-2021 has changed completely mate. The correlation that you are saying no longer works. All the altcoins do follow the same pump as bitcoin do. I mean there is no inverse proportion now a days. If bitcoin is pumping then altcoins are also pumping at the same time.
Moreover there are many many altcoins who don't even rely on the bitcoin movement since they have created their own economic environment and they play within that boundary only.
It could be just your good luck or time when things turned profitable for you. But, you must recheck your strategies beforehand now.