The question is your timescale. Here I present analysis for weekly investments. If we go up I expect there to be enough time to get back in and it does not matter if I miss a few weeks.

But when you invest on monthly scales or larger, then it is a very different story. I actually did an analysis for 2 month investment and that was 80% bitcoin, 20% cash and no ethereum at all.

But most important is to have good risk control. Bitcoin can go up 30% or down 30% in a week. If any of that is a disaster for you then you have too much risk.