If you're paying attention you can catch the next one.

** for example, if/when bitcoin dies, I expect there will be several coins competing to take that spot as the world reserve crypto - the one coin that everything else trades against. You don't even need to identify it specifically, you just need to recognize the 4 or 5 alternatives that might take the crown.

Back testing - go back a couple years to the eth crowd sale. Take 20% of your bitcoin total and divest it evenly into the top 4 contenders for dominance at that time. It doesn't matter if 3 out of those 4 fail, as long as you got at least some small amount into the one that survives. In this example it's ETH. 0.0005 at the opening, now worth ~0.035 ! That's like 70X return on that small side bet. Even if all your other bets fail, it just takes that one to pay off...

 (If none of the alts survive, then that's good too. That means probably it was bitcoin that survived and your main holdings are still in bitcoin, you've just spent 20% hedging your bet.)