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.
Where exactly did you get to see that people were buying more when the price was going up than when it was going down?
As for me, I think people are constantly buying cryptocurrency all the time. Yes, there might be some increase in the buying rate when the price is going up, although I can’t tell if that’s true for sure, but I do check on Coinbase at the times when the price of Bitcoin is falling and the buying is still more than the selling rate.
There are always traders who are constantly buying without minding the market situation. It means different traders are following different strategies on where to buy and where to sell hence we cannot assume that all the traders are buying even prices are increasing. Moreover selling at higher prices than buying place is the simple logic what all traders are looking for hence even people are buying in up-surge they must be waiting for relatively higher prices to sell out.