The portion of a position left open after partial profits are taken, held for a larger move with the rest already banked.
A runner is a structural answer to a psychological problem. Taking part of the position off gives the immediate reward that hyperbolic-discounting demands, while the remainder stays exposed to the outsized move that makes a trend strategy profitable.
The costs are real. Scaling out reduces average profit per trade in systems whose edge comes from full-size winners, and it adds commission and decisions. It is a trade of expectancy for consistency and for the ability to actually hold.
Define it in advance: how much comes off, at what level, where the stop on the remainder goes, and what closes it. A runner managed by feel is just a position you forgot to exit.
Original diagrams for the ideas on this page. Illustrative, not real market data.
Expectancy: the average trade. Forty trades sorted by outcome: 24 small losses and 16 larger wins. Weighting each side by how often it happens gives the average result per trade, marked here by the dashed line at +$120.
Educational only, not advice. Spotted an error? Post in Site Feedback.