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Through market analysis you will gain extensive knowledge which will make you a bigger investor in the future so you need to analyze the market before investing in Bitcoin. Even if you are a new investor you should plan your future based on past price analysis. Suppose you invest in Bitcoin, do you keep your capital on blind faith, which you should not. You will determine your strategy sophisticatedly through market study strengthen your earning base accumulation Bitcoin from disposable income. It is true that Bitcoin is still in its infancy and has already become a store of huge value. You need to consider why you should study the market. The answer to the question is that suppose you buy Bitcoin with the equivalent of $5000, before doing so, you need to analyze why the value of Bitcoin may increase or decrease in the future. Through each analysis, you will be able to imagine whether you should invest in one lump sum or divide it into several slots. Or you can accumulation Bitcoin continuously every week/month from discretionary income. Analysis of all the information about the Bitcoin market.
Another thing that we might be presuming about the guy with $5k is that he already has an emergency fund that is already equivalent of at least 3 months of income (or at least expenses), and if he does not have an emergency fund that is at least 3 months of expenses, then he may need to consider putting some of his available $5k into that.. . yet there is no reason to necessarily prioritize the emergency fund over investing into bitcoin, so he could choose to grow his emergency fund and the size of his bitcoin investment at a similar pace until the emergency fund gets to the size of at least 3 months of income.
Yes, if we assume that the guy has $5k and is interested in investing in Bitcoin he may have some extra cash as an emergency fund that is net investment fund, but he should not try to restrain himself from aggressively buying Bitcoin. I mean, if the guy has a net investment fund and also has some extra funds from which he can spend for the next three months or six months should his entire fund be available for single Bitcoin buy? The answer is that he should still divide it into a few slots since he is a newbie investor and he is committed to holding for the long term. Or if he is more confident about Bitcoin he can reduce the investment slot further. But I think he should continue to buy with market monitoring so that if for some reason the price drops, he can buy more. The idea that you have provided that if that investor has cash funds committed to investing he might indulge in luxury if he is likely to encounter that situation he would have to spend his entire net funds to buying Bitcoin regardless of the price. In my opinion Bitcoin is not a luxury, it is a long-term effort to build the future. At the same time the guy should continuously accumulate Bitcoin from his weekly discretionary income.