Bitcoin all ready graduated from volatility it has maintained the price of $1500 and will not crash like the speculations of some gold investors lol
Here in my opinion we should have both type of coins for the speed profit .
According to me buy the Bitcoin and invest the Bitcoin amount in the most stable and powerful altcoin like ETH , DASH , Montero , ripple , dgb etc and then left it with patience to wait to increase , probably most of the famouse altcoins get faster stability with constantly increasing price .
So in this way we can make our profit double , earning from altcoin investment of the Bitcoin and earning from the increase in the rate of the Bitcoin also .
While investment is small risky , but I think if you will do everything with patience then you will never got any loss in this field .