Well, Nowadays bitcoin is going up and sometime it could be cross $750, So its mean now only holding the bitcoin is best way, Actually, i don't think that now we should use the bitcoin in any other way. But instead of it, you want to use the bitcoin than i always say to trading or gambling, both are better than others.
If you will ask again that question after 10 years, than also my answer will be same, use the bitcoin in trading or gambling.
probably it is good to hold bitcoin until the end of the year.
well I say, gambling is not a good way to earn bitcoin. it is the worst way in my opinion. you probably can win hundreds coins, but it does not mean you will be win and win again. the risk is too high. I strongly do not recommended it.
I think the other way , that is safe or with lower risk, is signature campaign. mining and trading is good either, but they required skills.