So far it was best way to hold it. The problem is that no one knows what will happen in future, as you know there is no 100% sure investment.
Agreed. You can not be 100% sure about your investment that a profit will come your way but if you do not try don't expect your money to grow magically.
It could rise more, it could decrease, something could happen with bitcoin itself, laws could prohibit it, etc..
Everything is a risk. That's why only invest what you can afford to lose. In my opinion, to eliminate those risk, thou must also invest in altcoins so that if bitcoin dumps, you still have an altcoins that can make your recover from the loss you have got from one investment.
And the good part of investing(holding) in bitcoins is they are low risk unlike most assets or services but hoping that altcoins will absorb your
bitcoin losses is a gamble