Which do you prefer?

Hello Everyone, want to ask few questions here.
Short term or Long term investment?
Which is more profitable to you?
What coins do think that is good for long term now?
Feel free to comment your ideas and opinions.
I think you can invest long-term into bitcoin and short-term investment into day trading altcoin, you can see that the market is constantly fluctuating and very hard to guess, the price of bitcoin knit continuously adjust and variable It is very strong, so it is very difficult to trade successfully at this time. I believe that at this point you should only invest long term into bitcoin.