There's no such thing as 'gambling' when you know exactly why you're holding your coins. If you did a proper research on the coin you're holding, then HODL can become an easy strategy where you can expect benefits in the long-term without taking big risks, that's very different from gambling where you don't what the outcome could be.

price movements shouldn't matter if you're HODLing as you're looking at the long-term profits, not the small gains in the short-term.