What you said is not true, ginsan.
discretionary income is any amount of money that you still have after you pay your expenses.
Discretionary income does not need to be fixed or stable.
Sure, it is helpful to have stable and/or fixed income but it is not necessary.
If you say that a person needs fixed and/or stable income in order to buy bitcoin, you are adding an additional condition that is not necessary even if it might be helpful.
It is like saying that I need to have $100 every week to invest in bitcoin, and if I only have $50 this week or some weeks I have $10 and other weeks I have $200, and some weeks I do not have any, and the punchline is that there is a lot of variance in my discretionary income, yet I still can invest in bitcoin, even if those amounts and/or those frequencies are not known in advance.
Bitcoin is all about taking advantage to invest and be profitable at it, this may come by any chance and at any time,
for us to be an investor, we may not have to depend on having a discretionary income which some also called a fixed source, instead we can have one or two sources to the income being generated, then plan on the accumulation pattern for our asset and device a strategy to use like DCA, which could best be applicable as at when we are capable enough to buy and hold as the market dips and as we are having our income flow coming.
Doing this makes it a perfect and more convenient way to invest into bitcoin and hold,
by using different strategic entry points for an investment and also strategizing on the perfect timing for us to invest on the asset and hold, mostly which is when the market dumps, then we buy to sell when it pumps.The only thing that should qualify anyone to invest in Bitcoin is that the person must have figured out that he has a discretionary income, if not the person is more likely gambling rather than investing, our investment money should be a dependant of our discretionary income meaning that you are not investing with money that is meant to be use to sort out your other important needs.
There is no time of buying that is as perfect as as buying whenever you have your investment money readily available for investment and buy just right away, Bitcoin market is unpredictable and timing can be very complex and that is while the DCA strategy of accumulating Bitcoin solve this problem of timing the market because it allows investors to buy Bitcoin regardless of the price points, the essence of a consistent buying is to have a reasonable size of Bitcoin and hold for a long time 4 to 10 years or even more, so as an investor you buy at any market price points and not just to buy low and sell high.