It depends on what type of project the coin is holding and what will be the result output. Their are coins which i am holding from more then 12 months as their projects are very good and its result will be 10x on long term. Some i have sold it as soon as it hits exchange. Right now i am holding ICN, ICOB, VSL, TIME, this are some coins which i am holding from long and my view is another 6 months and the coin will give you 10x profit.