Retail participants as a group, assumed to be late and wrong - a label that is partly supported and heavily overused.
The usual evidence is that retail flows tend to peak near highs and trough near lows, which some studies support in aggregate. Aggregate tendencies say nothing about any individual, and plenty of professional money is late and wrong too.
The label's real function is usually rhetorical: it flatters the speaker and is used to sell the idea that you can be on the other side by buying something. Positioning data is worth watching as sentiment information. Contempt for a category of participants is not an edge. See exit-liquidity.
Original diagrams for the ideas on this page. Illustrative, not real market data.
The bid-ask spread. Buy orders sit below, sell orders above, and the gap between the best bid (50.01) and best ask (50.04) is the spread you pay to cross. Bar length shows the size resting at each price.
Educational only, not advice. Spotted an error? Post in Site Feedback.