Volatility-Adjusted Kelly Position Sizing with ATR and Margin Limits

Summary

This document outlines a proposed position-sizing engine for algorithmic trading. It combines Kelly sizing, which uses estimated win rate and payoff ratio, with volatility adjustment based on Average True Range and tick value. The stated goal is to reduce exposure when volatility rises and to respect broker volume limits and available margin.

The material describes the intended architecture and inputs, but provides no equations, implementation details, tests, or performance evidence. Its claim that the approach produces an optimal lot size cannot be assessed from the description. Kelly sizing depends on reliable estimates of trading outcomes, and ATR-based scaling does not by itself ensure protection from losses or drawdowns. The document is therefore a high-level description of a software library rather than a validated risk method.

Key ideas

• The proposed engine combines Kelly sizing with an ATR-based volatility adjustment.
• It requires estimates of win rate, payoff ratio, and stop distance as inputs.
• The described safeguards account for free margin and broker volume limits.
• No formulas, testing results, or evidence of improved trading performance are provided.

Tags

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