What do you mean by bitcoin investment? You should elaborate a little more on this. It is not clear exactly what you want to ask, it is always better to be clear to get the right answer. If you ask the best stock exchange to buy bitcoin, you can see it by looking at coinmarketcap. If you want to ask when is the right time to buy bitcoin, investor friends may give an answer, but everyone's investment is their own. If it is up to me, enter this market from somewhere before it's too late and then you will learn it yourself.