the future of altcoin is wide open and altcoin have the potential to jump to the highest price in the future. but you need to analyze one by one so you can find the altcoin that will give you a big profit. but sometime, analysis the altcoin will be difficult since we know that every altcoin is depended on bitcoin price so we need to always check what is bitcoin trends so we don't miss something and we can always make a profit.
I agree it's tough to predict altcoins future prices but not all altcoins are depended on bitcoin price. When the BTC market will increase yup surely the altcoins market will increase but most of the altcoins price will increase if any good news comes from dev team or any big companies invested means people will start to buy the price will increase. I am not sure all altcoins future will be bright but out of 100, i think min 10% coins prices will increase.
The only good thing right now that everyone must know about that because in fact coinbase will be started to support ERC20 asset which mean that opens a lot of possibility to the security token to be adopted by US investors through use the coinbase exchange site and i think another US based exchange will be following it soon.