What is the best methods to protect altcoin from hacker?
take care of your private key, passwords and dont click any suspicious link that has been sent to you through pm, shared on any social media sites, etc. the only reason why hackers have the access on your account is because they successfully get your key.
I keep my coins by holding them. because the level of security I get for Altcoin that I have is quite high when I hold it. so to produce such a thing I use my coins to be held in the long run to generate profit and security on my coins. so this will be good for the future.