I have seen the price of bitcoin is very high and has exceeded 15000 $ for one bitcoin, and now the price of bitcoin is under 10,000 $ and maybe this is my chance to buy bitcoin as much money as I have and hope to get enough profit for my economy in the future.
am I wrong with this step?
I think, you are not wrong with your step because everyone has its own strategy on earning money. That's your strategy to earn more, but you can't predict when the bitcoin price will increase or decrease. you need to check everytime the value chart of bitcoin to know when you will exchange your coins.