It was altcoins that have a small price. It was because right now, I am stopping to trade in future market because of some reasons 
I am sure that every trader will have their own strategy and also comfort to trade Bitcoin or altcoins.
For me, why I chose altcoins because of some reasons:
- Have a small amount of capital
- Not targeting a high percentage of profits
More options, moreover under $1 
- Some altcoins are easy to analyze and predict for short or long (but this is not really easy, only easier than other coins)
- Can earn  more profits even with small capital (once more, there is no guarantee it will be like this every time)

But, there is no guarantee that it will also work for other people, everybody has their own choice based on the experience or even the most appropriate ways to do