Is it possible that all bitcoin users who invest at the same time will benefit all? and no one user loses money?
Not that is not possible, you need to understand that if you want to earn money then someone else needs to lose money it is not complicated, money is not going to come out of nowhere someone needs to inject money in bitcoin and other cryptocurrencies and those that bought at a cheaper price can now sell for a nice profit selling their bitcoins to the ones that are buying right now, it is a very simple concept, does this mean that at the end there are going to be a huge amount of losers? Yes, but that happens in any investment as well.
