Invest is the right thing to do, because if you invest your BTC it is high possibility to earn income. However, saving bitcoin had no effect you can only wait the fluctuation of BTC in the market, you cannot predict if the value of BTC were getting UP or DOWN.
That is what i'm talking about, investing bitcoin is one of the best thing to do rather than just saving because saving will not help you to become millionaire because it will take time for your bitcoins to make you a millionaire while investing will help you to grow your money and if you do compounding then you will have a faster way to become a millionaire.
Both are good but investing will generate income, good for people who are risk takes since bitcoin is here to give them opportunity.
I have a little investment in altcoins as well and I hope it will grow overtime.