Tool preview
Position Sizing Worksheet
Estimate position size using a simple risk budget, then sanity-check concentration versus your broader portfolio. The worksheet is designed for clarity: you can see inputs, assumptions, and outputs on one page.
Risk budget input
Set a percent of portfolio you are willing to risk.
Scenario sensitivity
See outcomes across a range of drawdown assumptions.
Review fields
Track thesis status, catalysts, and invalidation triggers.
Many portfolios drift because the original reason for each position gets fuzzy over time. Our templates are built to preserve your decision record: what you believed, what would change your mind, and what data you planned to monitor. This reduces reactive trading and helps you assess results honestly. The goal is not to avoid mistakes completely, but to learn faster by making your assumptions visible.
Each tool includes short guidance notes that define the fields and provide examples of what a clear entry looks like. The examples are generic and do not recommend any specific security. If you prefer to work in a spreadsheet, you can use the structure in your own file; if you want a printable workflow, the same structure works on paper during your reviews.
A structured document for your thesis statement, key drivers, downside cases, and what evidence would invalidate the idea. It encourages you to separate facts, assumptions, and opinions so a later review is objective.
A repeatable checklist for exposure, liquidity considerations, and correlation assumptions. It helps you avoid accidental concentration by sector, theme, or single factor such as duration or commodity sensitivity.
A calculator to translate a risk budget into a position size and to estimate how a rebalance changes overall concentration. It is designed to make your assumptions explicit, so you can adjust them when volatility or thesis confidence changes.
This on-page calculator demonstrates how a simple risk budget can translate into a position size based on an assumed adverse move. It is a learning aid, not a recommendation. You are responsible for selecting assumptions and for confirming any constraints set by your broker or local regulation.
If you are new to sizing, focus on consistency: use the same approach across positions and record why you changed any input. The review notes in your thesis sheet are often more valuable than the number itself, because they show how you respond to new information.
A practical workflow is to run a short review on a consistent schedule. Start by scanning your portfolio for concentration: has one position grown large relative to the rest, or have several holdings become correlated through the same macro driver? Then read your thesis sheet for each top position and update only the fields that changed. The goal is to keep the record current, not to rewrite the thesis every week.
When you consider a new stock, fill out the thesis sheet first and use the sizing worksheet last. This ordering reduces the temptation to justify a position after choosing a number. If a thesis is unclear, sizing larger rarely fixes the problem. If you want broader market context to pair with the review, our Market Insights page provides definitions and summaries that complement this workflow.
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