Because it fluctuates every year. It is normal that people are buying btc to increase the value and sell their bitcoin also when the value increase. The supply and demand applied in bitcoin that's why it is increasing and decreasing at the same time. People who are not good at trading makes bitcoin comes down also.
Yeah falling prices are a natural thing of bitcoin price changes in the market, and we don't need to panic because of this, but the question is what makes the bitcoin price steadily declining in recent weeks? because there is nothing surprising about bitcoin price changes this month
It is good to hold your bitcoin at the time of falling price, as you said it is very natural for bitcoin that it often decreases the price but the suddenly it rise very high, so if some people have sold their bitcoin which made the price down it does not mean you also become worry, sell panic and contribute to the price to become more than this, dont panic as it will be your contribution in dumping, so hold and let it be high.