That is right. But I would suggest to not expect high with blogging these days. SEO is quite tricky now due to regular google updates. Not to mention, that there are bunch of competitions in the market now. What I suggest is to find for a very specific niche in bitcoin and capitalize from there. That way, you can have a chance to dominate the search ranking in that very particular small niche that is not yet saturated.
But investment won't give you steady income and to make profits from it you also need to wait for a long time, and may be sometimes if your investment doesn't work then it can be a loss for you.
I guess the best way to give you steady income is going to be a virtual assistant or be a freelancer that is going to give you a chance to earn decent because you are employed and hired by a company no matter what is its size, big or small. As long as you hired by them and you have contract agreement then that is going to give you steady income.