$BTC rallies hard, majority of "alts" drop as BTC is the main liquidity provider to #crypto (right now) and no one wants to sell BTC.
Value of "alts" in *BTC terms* then drops until whales choose to cycle into "alts." Then...
Those "alts" rally harder than BTC did because they are higher risk, gaining in *BTC terms.*
The whales can then cash their "alts" out for more BTC than they started with. And so they "make BTC" :-)
Every other #cryptoasset is higher beta than it, meaning it'll move more to the downside (when people are panicking) and also more to the upside (when people are ebullient).
The right calcs and therefore comparisons will depend on the value capture pathway of the native cryptoasset: static1.squarespace.com/static/5a479ee…
Over long term, expect them to fade away as liquidity broadens beyond BTC, market gets more discerning, shorting matures, etc etc.