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How do you guys think about this idea of mine for my colleague? Can it really be helpful to him in the long run or it may just obstruct his original plan killing the whole idea? Please all opinions are entertained but whatever your opinion might be, also try to put the length of years involved into consideration. (16 years)
Pure investment and it will always depend. For me, as long as your friend will not end up broke even though his investment every month will be gone, he will still be able to live after retirement even without the investment (just in case something bad happen). In short, he will not 100% rely on his investment in Bitcoin after he retires.
Your colleague must consider also if that 20% of their monthly salary of him is too much or not so? Is he willing to lose it every month?
16 years is a very long time, Bitcoin is still 14 years since it was created.