Definitely trading , everything else is most of the time a scam and gambling make you greedy with time and you eventually lose everything If you don't want to stop. In the case of trading , If you lose there is no one to blame but your self unlike of gambling where you accuse the website of scam or cloudmining that keep closing it doors and run away with funds etc...
Why did not you think of signature campaigns? It is also a form of earn very high profits. If trading needs the capital and high economic skills, signature campaigns do not require such high demands. In addition, the trading still exists a certain risk ratio and the signature campaigns is almost zero rate, only profit is less or more.
Earnings from signature campaign will depend on the level of rank that you hold if you have higher rank then you will get paid higher for doing the same amount of work that a lower rank member will do and its the easiest and safest way to earn bitcoins and once your earning reaches to 0.1 btc I think that would be the best time and capital to invest in trading.