From my experience, it is profitable. I prefer short term than long term though in some instances I am forced to hold when prices don't go my way. My technique is that when the current price of altcoin is below by 10% its average price, I buy and then when prices go back to its average value I sell. I don't mind making many 5% trades per day.
Actually I have a lot of experience in trading. I experience to have a huge profit, but I also experience losses. But the expert says that it was a normal instances for a traders.
I would like to share my great experience in trading, bitcoin prive before are too low , that why I tried to buy a lot of it. Its not my intension to hold it for a long time. But when I saw it that it grows everyday then i persue it till now that I have a great income now.