From the experience of last couple of years, if you mean to get profit, you should know when to buy and when to hold. Just holding for long time won't make you rich. What now be bought by 1$ can't be done by 2$ after 10 years.
I agree that holding for a long time won't make you rich.It's still base on your own experience, try to study and do some research about the altcoins or bitcoin that you are prospecting to invest.