There are 3 popular ways to earn money:
- Bounty Campaign (Need High Rank Account (Very Low Risk | Can Start From Zero)
- Mining (Low Risk | Need Large Capital)
- Trading / Investing (Very High Risk | Can Start From Small Capital)
So the only answer for your question is trading / investing But Just If You're an Expert in This Field.
what you describe is not truly investment, like bounty or trading. mining can be used as a good investment but it certainly has risks depending on the site you choose or the mining method you choose.