Martingale and Anti-Martingale Position Sizing After Trade Outcomes

Summary

This text compares two approaches to changing trade size after wins and losses. Under the classical Martingale approach, a trader begins with a minimum position and increases size after each loss, aiming for a later winning trade to recover the losses in the sequence. After a win, the position returns to its starting size. The text explains that this does not create an edge; it concentrates results into frequent small gains and less frequent, larger losses.

The Anti-Martingale approach increases size after profitable trades and resets to the initial size after a loss. The text recommends defining a limit on consecutive increases. It gives no empirical comparison, market-specific guidance, or formal treatment of capital constraints and risk of ruin. Its description is conceptual, and the numerical sequences are illustrative rather than evidence of expected performance.

Key ideas

• Martingale sizing increases position size after losses to seek recovery on a subsequent win.
• Anti-Martingale sizing increases position size after wins and resets after a loss.
• Martingale redistributes gains and losses rather than creating a trading advantage.
• The text advises setting a cap on Anti-Martingale size increases but provides no performance analysis.

Tags

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