Personally I do think researching and holding a few cryptocurrencies that are promising is a much better approach than trading for short term profits. Short term trading is essentially gambling, and research has shown* that most people lose money in short term trading.

However if short term trading is what you're after, you're looking for high volatility coins. You can make (and lose) more money on them with less leverage than coins with lower volatility.

* It's true in the equities market at least, but it's likely true in crypto too.