Just some additional F.Y.I. Some already know this, some don't.
Ethereum is not money, but it does have value. So, more like an equity.
Bitcoin is money and has value.
Neither are fiat. Although BTC is legal tender in one country (so far), (El Salvador).
Now to the why. Money is fungible (one unit is interchangeable with another), durable (it can be used repeatedly) , divisible, portable, acceptable, uniform and limited in supply. Bitcoin meets all of these criteria plus its supply isn't just "limited", it's fixed. ETH is not limited in supply (since its supply can and has been, changed over time). Bitcoin adds an additional feature...immutability. It's extremely resistant to change. This is a major feature (not a bug) when referring to "sound money".
Is any of this relevant to investors? Sure, depending on what your personal goals are, and what you expect to happen in the future.