for me holding btc is just like investing btc holding btc would be good if you have patience , if you have alot of btc you can earn alot of profit because the unstable price of bitcoin. investing your btc on gambling site would be good too it just like holding btc or investing on a cloud mining site.
You are right nowadays if someone will like to find a way for a faster income.e source then they have to invest in Bitcoin only and do not have to invest in any other way or scheme as the faster profit nowadays is from Bitcoin only.
The best way you can invest your bitcoin is to be smart in your earning.
But some people tend to be greedy and look for a fast earning so they jump into gambling so they lose their money, so it is a very bad idea, trading on the other hand is less risky and has so much potential to make you some good profit.