Based on the understanding and knowledge of following up with the cryptocurrency for the past 6 month, my inference is that the cryptocurrency is highlt volatile.
Is it a good approach to stay invested for long term in the altcoin space?
You do not tell to us in which altcoin you are thinking about being invested for the long term, I say this because there are many altcoins that are very good and that without a doubt deserve that you hold those coins for a very long time, but most of the altcoins especially those that are being released right now are not very good and I will not recommend anyone to hold them.