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.
I know day trade is profitable because we can make daily income in percentage.
But for unexperience and unskill trader please dont try this since it will put your capital in high risk.