Bitcoin prices fluctuate and will continue to change so you can buy bitcoin at any price at any price because there will be more price increases and reach the price you buy, we just have to be patient and be able to control emotions. if I have to have good knowledge about bitcoin, then I can do it to buy and sell, I can't search the market. All need market analysis. When do you have to buy and when to sell. Not all decisions are good at the same time. we only need to pay more attention to risks and opportunities.