PPolySim OS
For Students · Kelly Criterion

Kelly Criterion for a retirement fund

Built for students learning it for a class or exam. See the concept move instead of memorizing formulas — and check your homework intuition. Simulate a retirement fund live below — adjust the inputs and watch it respond, right in your browser.

Kelly CriterionLive

Controls

Presets

The Kelly criterion gives the bet fraction that maximizes long-run growth: f = (bp − q)/b. Bet less and you grow slower; bet more and volatility eventually ruins you. Many practitioners use a fraction of Kelly to tame the swings. Educational tool, not financial advice.

▶ Run in Python

Data Inspector

Kelly fraction10.0%
Edge (bp − q)0.100
Half-Kelly (safer)5.0%

Governing equation

Reading this result: Kelly stakes 10.0% of your bankroll per bet — the fraction that maximizes long-run growth; betting more raises volatility without raising growth, and eventually courts ruin.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

or unlock everything with Pro →

More with Kelly Criterion

Frequently asked questions

Is this good for students?
Yes — this version of "Kelly Criterion for a retirement fund" is framed for students learning it for a class or exam. See the concept move instead of memorizing formulas — and check your homework intuition.
Do I need to install anything?
No. It runs in any modern browser, free, with no account required.