I notice that when there the price is going up so many people are joining the train and they also buy because the price is going up and they are going to make a profit, why people are not buying when it is down when the price will eventually go up and they can make a lot of profit.
this is what is called not wanting to be left behind or what is called the FOMO syndrome...
a professional trader/investor will definitely only buy an asset when the price goes down but newbies will only buy an asset when they see the price is going up in the hope that the asset price will continue to rise.