Not sure if you can consider buying tokens from ICOs part of trading. I would consider trading to be something like really trading on exchanges that offer coins that are already out of the ICO stage. It's still not a sure fire way of earning though, since there is still a lot of risks involved in trading to be considered as something that could make you profit the whole time.
It depends.
Many projects are offering bonuses especially in preICO stage, buying tokens, receiving bonuses and selling them as soon as tokens hit exchange, then waiting for deeper dump to rebuy back is something what many...
buyers are doing and it can be considered as trading.
If we are talking about people who are buying tokens during preICO/ICO and holding their tokens until project become big and their investment reach 10-100X or project fail and they become bagholders, then we are talking about investment.
Both methods have gambling elements.