Expected Payoff, Market Order Flow, and Position Sizing in Forex

Summary

The article frames price movement through market and limit orders, spreads, stop levels, and the distinction between trending and range-bound behavior. It then builds expected-payoff equations from the probabilities and outcomes of stop-based exits and signal-based exits, extending the setup to strategies with multiple stop configurations. Profit factor is presented as a comparison of expected gains and expected losses.

The author argues that a strategy operating in a chaotic market has zero expected payoff before trading costs, and that an edge requires predicting price movement over a defined interval. The article also recommends adjusting lot size in response to performance and trading against recent half-waves, presenting these as ways to improve results. These recommendations are not supported by reported backtests or quantified evidence, and the position-sizing claims should be read as the author's opinions. The equations provide a probability-based framework, but they do not establish that the proposed trading methods are profitable.

Key ideas

• Expected payoff can be expressed as a probability-weighted sum of gains and losses.
• Stop exits and signal exits can be modeled as separate outcome groups with conditional probabilities.
• The author proposes that a chaotic market yields zero expected payoff before spread and commissions.
• Profit factor compares expected gains with expected losses.
• The article suggests adjusting position size and trading against recent price half-waves, without presenting performance evidence.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.