Both are good depending on the token. If I see some token got dumped hard because of certain news, I expect a dead cat bounce and I trade it for a few days. Also, if I see a token moon because of something very small, I try to short it.
Long term investment is different, though. I can help make really big gains. All the 100x we hear about are from people who did long term investments. This kind of investment only works if we do our research in some strong new projects. I recently researched on Veil Project and I am holding it for long term. The project has experienced team and is making privacy coins better by making mutliblock transactions, private basecoin transactions through RingCT technology, and an easy to use wallet.