position-sizer

Calculate trade position size using Fractional Kelly and ATR methods.

Updated Mar 1, 2026

Search Tags:#risk management #portfolio management #trading #position sizing #atr #kelly criterion

Ready to run

npx skills add https://github.com/mqzkim/trading --skill position-sizer-mqzkim

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: position-sizer
Source: https://github.com/mqzkim/trading/tree/main/.agents/skills/position-sizer
Command: npx skills add https://github.com/mqzkim/trading --skill position-sizer-mqzkim

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill calculates the optimal position size for trades based on risk management principles, ensuring alignment with individual portfolio size and risk tolerance.

Core Features & Use Cases

Fractional Kelly Criterion: Calculates position size using a conservative fraction of the Kelly criterion.
ATR-Based Sizing: Determines position size based on Average True Range (ATR) to account for volatility.
Conviction Adjustment: Modifies position size based on a composite score reflecting confidence.
Use Case: A trader wants to determine the exact number of shares to buy for a new stock, considering their portfolio value, the stock's volatility, and their confidence in the trade.

Quick Start

Use the position-sizer skill to calculate the optimal position size for AAPL with a portfolio value of 100000 and a score of 75.

Frequently Asked Questions about position-sizer

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I calculate optimal position size for a trade using ATR and Kelly criterion?▼

Calculate optimal position size by combining Fractional Kelly criterion with ATR-based volatility metrics to determine target weight, shares, and stop-loss levels for your portfolio. This adjusts your risk exposure based on stock volatility and conviction score.

What is Fractional Kelly position sizing and when should I use it?▼

Fractional Kelly position sizing is a conservative risk management method that calculates trade size using a fraction of the Kelly criterion formula. Use it to align individual trades with your total portfolio value and defined risk per trade limits.

How do I factor conviction score into my trade sizing?▼

Factor conviction score into trade sizing by using it as a composite adjustment modifier that scales the calculated position size up or down. This reflects your confidence level in the trade alongside ATR volatility and portfolio risk constraints.

Can I use ATR-based position sizing for personal portfolio management?▼

Use ATR-based position sizing for personal portfolio management by inputting your portfolio value, symbol, and composite score. It calculates dollar amount, shares, and stop-loss tailored to individual traders managing defined risk per trade.

What inputs do I need to calculate shares and stop-loss for a new stock trade?▼

To calculate shares and stop-loss you need the trading symbol, total portfolio value, and a composite conviction score. These inputs determine target weight, exact share count, dollar allocation, and stop-loss price.

When should I not use Kelly criterion for position sizing?▼

Avoid using Kelly criterion position sizing when you lack a defined conviction score or maximum position limits, as the calculation relies on these to apply fractional adjustments and enforce risk management constraints for individual trades.