Bro! The whole point of btc is that you can do both at the same time!
BTC inflation makes it so that saving btc is the same as investing in it!
True, my biggest stash of coins are safe on hardware wallet, I dont use them for trading or anything. So you can say its saving with potential of growing to be really nice investment. My biggest problem and worry is what price will be my exit point, I still havent decided yet.
Both of you my mate , are right but I think the OP is asking for the saving of money in the form.of fiat in bank and for investment he means to invest your money in the bitcoin and in other investment services like ICO or altcoin .
Well here I will suggest to invest his bitcoin or money . Because if you will run your money in the world then the value of your money will remain stable according to the price in the world , But if you will save your fiat money in bank then it will remain in a place to remain at very low price value with the time , because interest you will get for your money deposited by you in bank will not give much profit that what you will get in the wise real investment .