---
title: "Position Size & Concentration Decision Tree"
description: "Swoopr Investment provides a decision tree for position sizing and concentration in a stock portfolio: how to size a position relative to thesis quality."
canonical: https://www.getswoopr.com/learning-paths/stock-investing/position-size-concentration-decision-tree/
source: "Swoopr Investment: https://www.getswoopr.com"
---

## Direct Answer



Position size should be determined after thesis quality is assessed, not before. A high-quality, well-documented thesis with clear break conditions justifies a larger position than a poorly documented idea, regardless of how strongly you feel about it.






      

# Position Size and Concentration Decision Tree



Position sizing is not a formula for maximizing returns; it is a framework for managing the consequences of being wrong. This decision tree helps you size positions relative to your research quality, not relative to your conviction.






      






## Key Takeaways



- Sizing comes after thesis quality, not before; conviction without documentation is not a sizing input.
- Concentration has hidden dimensions: correlation risk, liquidity risk, and information risk all affect effective concentration.
- Use bands of acceptable size (2% to 5%, for example) rather than false precision.
- A position that would force you to monitor it daily is too large for your research capacity.
- Maximum position size should be defined in the investment policy before any specific stock is analyzed.






## Sizing comes after thesis quality



The decision tree begins with a thesis quality gate. If the thesis has sourced facts, explicit assumptions, defined break conditions, and a written scenario analysis, it qualifies for a standard-sized position. If it lacks any of those elements, it qualifies only for a pilot-sized position. The idea is not evaluated on conviction; it is evaluated on documentation quality.



## Concentration has hidden dimensions



Owning five stocks in the same industry is more concentrated than it appears in dollar terms. Effective concentration accounts for correlation between positions, liquidity relative to average daily trading volume, and information quality: how well you actually understand the business. A position you understand deeply is less risky than one of equal dollar size in a business whose model you cannot explain in plain language.



## Use bands, not fake precision



Expressing a position size as exactly 4.73% of the portfolio implies a precision that does not exist in the underlying analysis. Use bands: 1% to 3% for pilot positions, 3% to 7% for standard positions, 7% to 10% for maximum positions in a concentrated portfolio. The band acknowledges uncertainty; the upper limit of the band is the risk control.






## Applied Exercise: Evidence and Interpretation



Use a company you already follow or a fictional company. Begin by writing the decision question. Then create this two-column note:



| Evidence | Interpretation |
| --- | --- |
| What the primary source reports | What you think it means |
| What changed from the previous period | Why the change may matter |
| What is still unknown | What would resolve the uncertainty |



Add a third column only after the first two are complete: **Decision impact**. Mark each item as *supports*, *weakens*, *neutral*, or *unresolved*. This keeps evidence collection separate from persuasion.








## Frequently Asked Questions


        
### Is this page investment advice?



No. It teaches a research and decision process. The examples are educational and do not recommend any security or allocation.




### Do I need to finish every Swoopr stock page before using this?



No. The learning path intentionally points to deeper reference material only when it becomes relevant to the skill being practiced.




### How do I know when I am ready for the next stage?



Use the stage gate. Progress when you can produce the required artifact without relying on the lesson as a script and can explain both the conclusion and its limitations.




### Should I use a stock screener or AI summary instead of filings?



Those tools can help with discovery and organization, but material facts should be checked against the closest available primary source when practical. A summary is not a substitute for the evidence it summarizes.




### What if the evidence conflicts?



Preserve the disagreement. Do not average conflicting signals into a false sense of certainty. Identify which evidence is more direct, more relevant, and more current, then record what would resolve the conflict.










## References



- [Swoopr Portfolio Review Center](https://www.getswoopr.com/portfolio/review/)
- [FINRA: Asset Allocation and Diversification](https://www.finra.org/investors/investing/investing-basics/asset-allocation-diversification)
- [Investor.gov: Asset Allocation and Diversification](https://www.investor.gov/introduction-investing/getting-started/asset-allocation)
- [FINRA: Know What Triggers a Margin Call](https://www.finra.org/investors/insights/margin-calls)








## Disclaimer



This page is for educational purposes only and does not constitute investment, financial, or trading advice. Swoopr Investment is not a licensed investment advisor; consult a qualified professional before making investment decisions.












S




By [Swoopr Editorial Team](https://www.getswoopr.com/authors/swoopr-editorial-team/)



The Swoopr Editorial Team researches and writes our technical and fundamental analysis education content, drawing on established market-structure and indicator methodology from primary industry sources. Content is reviewed for accuracy before publication.



Questions or corrections? See our [corrections policy](https://www.getswoopr.com/legal/corrections-policy/) or read more about our [editorial standards](https://www.getswoopr.com/legal/editorial-policy/).