When bitcoin prices were faster than 10K last year, I was very worried about too many bubbles. But when bitcoin prices continue to rise to 15K, more people believe that this price is only a starting point. The subsequent rapid decline was a proof of how serious the speculations of bitcoin were. I think investing bitcoin luck is also very important. What's more, we must have our own buying and selling plan. We all know that it will go to the moon again, but it doesn't sell, so it's hard to really earn money.