When a new token is listed on an exchange, its price usually goes down because early investors (who bought at presale and so on) take their profit. If the token's tokenomics, initial distribution and token release schedule are good, initial investors won't be able to sell everything, but they will sell what they can and this will decrease the price. The price then usually spends a few days or weeks searching its bottom and stabilizing around it, and the trading volume is very low. This is when you pay attention. If at some point there is a big spike in trading volume on the 4H or the daily chart, this for me is a really good buy signal. This is just my opinion of course, not financial advice. I would like to hear what others think.