Alt coins enjoy the same principles that any other asset does: the Law of Supply and Demand prevails.
The single most important factor is if others value the currency and seek to obtain it. The more people that seek to buy it, versus the supply of the Alt coin, ultimately determines its value.
Secondly, does the Alt coin have liquidity? If it is not easily bought and sold, the value will not rise.
Cheers!
So true! Thanks for sharing. I always look at volume and liquidity. There's nothing worse than getting stuck with coins that you're desperate to get rid of. Also, best way to see the supply and demand is by looking at the order book. It'll give you an indication of just how easily the price will move up or down.