You look at the chart, it keeps rising, and you feel anxious and uneasy... It pulls back a little, and your mood eases slightly... But the pullback is not much, and you are reluctant to buy in... Emotions keep repeating and accumulating (key point)...
They say it will rise further;
They say there are still positive factors;
They say the target price is this much;
They say it will rise by this many times...
So, you make a bold decision, gamble it all and let it be...
Then it officially starts to drop...
Note: This is a general principle of human behavior in groups.