Matt describes it as follows in a post on 28 Nov 2022:

"The A's are pretty good, Amateur buying at tops, and Amateur selling at lows. Basically it's volume declining and smaller size prints in volume as price goes up or down; for example in an uptrend when price gets exhausted, you get the late buyers, typically individuals who trade small size few hundred shares, not institutions who are large prints. During downtrends you get the very late sellers or shorts who are selling very oversold conditions."

Search for amateur; that should do the trick