Can you use BTC without mining?

Question: Can I just buy/sell/trade to btc futures market and hold it and still be profitable? I mean with money you'd need to invest it in stocks, bonds, and etc to make more cash and simply holding on to cash over the long term means the same as losing money. Is this also true with BTC? Will I be losing money if lets say I buy 2 BTC coins and just leave it alone without investing it?