Term · Portfolio & Execution
Position Sizing
In briefPosition sizing determines how large an individual position is - derived from conviction, risk, liquidity, volatility and potential loss. For small caps, the sizing decision carries more weight than for liquid blue chips, because mistakes are harder to correct.
Definition
Determining position size on the basis of conviction, risk, liquidity, volatility and downside.
How it is calculated
Formula. No standard formula; often a combination of maximum weight, volatility budget and liquidity limit.
Why it matters for small caps
In the small-cap space, position size matters more than for liquid blue chips, because mistakes are harder to correct.
Common misreadings
- It is often derived from upside alone; downside, exit duration and dilution risk must also feed into it.
In the process
Frequently asked
What is position sizing?
It is the deliberate determination of the share a position takes up in the portfolio. The basis includes risk, liquidity and conviction, among other factors.
How do you determine position size?
Usually you combine a maximum weight with a volatility budget and a liquidity limit. There is no fixed standard formula.
What mistake happens in position sizing?
Size is often derived from price potential alone. Downside risk, exit duration and dilution should be factored in as well.
Related terms
Sources
Primary
CFA Institute – Active Equity Investing: Portfolio Construction
https://www.cfainstitute.org/insights/professional-learning/refresher-readings/2026/active-equity-investing-portfolio-construction
https://www.cfainstitute.org/insights/professional-learning/refresher-readings/2026/active-equity-investing-portfolio-construction
Methodology
CFA Institute – Trade Strategy and Execution
https://www.cfainstitute.org/insights/professional-learning/refresher-readings/2026/trade-strategy-execution
https://www.cfainstitute.org/insights/professional-learning/refresher-readings/2026/trade-strategy-execution
Education only, not investment advice. Ranges and thresholds are didactic orientation values, not an official standard.