Crypto currency is not necessarily zero sum. This is a brief explanation with just some of the reasons. In your example where people are using crypto as a store of value over other currencies, at first glance it seems zero sum, for example: demand to hold XRP (ripple) goes up, demand to hold USD goes down. What is missing is one of the reasons demand for XRP might go up and USD go down. If XRP offers advantages over USD such as ability to store value outside of a bank, ability to transfer that value instantly to anywhere in the world without paying bank fees etc. In this case the person who switches from USD to XRP can be said to have gained something in the transaction. Now of course there are disadvantages in that switch as well, so it's difficult to tell if the person will have actually gained value. To the extent that crypto currencies allow people to do things that they couldn't otherwise do, or do things in a way that they prefer, then value has been created, not just shifted as would be the case with zero sum. Another thing to consider is that in any voluntary trade value is created. If I buy an apple for a dollar, an apple and a dollar change ownership (seemingly zero sum), but value has been created since I value the apple more than I valued the dollar, and the seller valued the dollar more than he valued the apple. We each have something more valuable to us than before.