Last year alts rise a lot. I dont know the average percentage. But when I check coins in the market at year 2013 lots of them dead now (too low ranks). probably new tech coins won them (like peercoin, namecoin, ixcoin etc)
Also we are following new ICO s and most of us expecting too much gain from new coins which are not at the market. If our ICO expectations will happen, when they added to market, current market coins will go down. kind of paradox
I'd say risky because not all altcoins are potent to have a price increase. Altcoins are known to be best for short term holding. Particularly ICO tokens or newly listed coins, these cryptos are mostly having a short period of increase and eventually, market downfall. But at this memt, holding is the only option due to the downtrend.So despite of being risky, we should still hold and wait.Also we are following new ICO s and most of us expecting too much gain from new coins which are not at the market. If our ICO expectations will happen, when they added to market, current market coins will go down. kind of paradox