Investing in bitcoin requires that you should have a stable source of income that makes provision for discretionary funds after all necessities have been taken care of, anyone without a source of income should not invest in bitcoin untill the they have secured a good source of income, this is because without money you can't invest and you don't just plug money from trees, you need to work for it, some work harder than most depending on the job/business, and your income has to be high enough to yield discretionary funds before you invest, because you should never invest with the money meant for paying tax and footing your bills, and also while investing in bitcoin with your discretionary funds, a percentage of your discretionary funds should be saved up for emergency purposes so you don't end up selling your bitcoin when you run into a financial crisis and are in dire need of money.
It is actually good and advisable to have a secured job or work before starting an investment but then I think sometimes the most important thing is starting first because someone who is serious and determined will take responsibility and make sure to keep on accumulating and holding. Over time I realized that having task at hand sometimes makes people to become proactive because if you haven't start at all you won't bother yourself to make sure to keep your investment but if you have started, some persons will begin to sort out things and things they were not doing before they will began to do it just to ensure they meet up with there investment and this kind of person they know how to economize and manage things because that is just the stage they find themselves.
All you just need is a source of income to get going because without a source of income, their is no way you can keep on investing consistently on the longer run, it might not necessary be a salary paying job, it might be a business or anything that you does that put foods on your table, once you have a source of income coming in, their is nothing stopping you from investing in Bitcoin, along the line you can start building your emergency funds, and take note that while building your emergency funds, make sure you build it to a level that will be strong enough to sustain you for like three months, so that no matter the size of the emergency situation, it will be able to carry you without you tempering with your Bitcoin holdings.
The only set's of people that I would advice not to invest in Bitcoin now is those people that don't have a source of income, because they can barely feed themselves, so what they should be thinking now is how to get a job or a source of income not investing in Bitcoin, because if they do with any money that got into their hands, it will be just a matter of time before they sell it off just for survival.