This is also a complicated question
Up to a point where such overgeneralizations become meaningless and utterly misleading. To put it differently, you can't possibly say that day trading is gambling while long-term holding is not as both can be gambling just as easily as they may not. Obviously, it all depends on the individual engaged in any of these. It should be clear that people can lose money irrespective of their investment horizons (short term versus long term) just as they can earn profits riding both short-term volatility and global trends
Whereas we entirely wait in long term trading to expect the price reach above our limits and than we place sell orders. Usually long term trading can be profitable and hence is considered by various traders. Short term trading will really require a lot of knowledge and ability to graph the price index to see profits growing up.