Holding is good for top-in-the-future coins or if you are a dumb in trading. Trading is perfect is you have some-working strategy and some experience in that. Trading allows to achieve results much, much faster than hodling. Hodling is a passive thing that won't help you get to the moon. Honestly, hodling is the best strategy for most traders/investors.
Trading is good because in holding your coin you will not be aware of it that when the price of the coin will increase as no one know about the market change but in trading you can sell your coin at high price and you will keep check on Market all the time. So better to trade or apart from trading you can put some bit coins holder for long term.