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.
by holding Altcoin able to keep the coin from various attacking circumstances. and to hold it is also very capable to increase the coin in the future. so I often hold the Altcoin I have to secure it. with safe coins will avoid hackers.