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Portfolio Stats – Kelly Criterion Calculator
x402
Portfolio Stats – Kelly Criterion Calculator is a paid API for AI agents from portfolio-stats.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).
Computes the Kelly criterion optimal bet fraction, growth rate, and overbet threshold for a given win probability and payoff ratio
Price / call$0.02
Success—
StatusUnknown
How this service works
Kelly criterion fraction for a stated win probability and payoff, with growth rate and overbet threshold. NOT advice.
Output
Returns the full Kelly fraction (optimal bet as a proportion of bankroll), an optional specified fraction of Kelly (e.g. half-Kelly), the log growth rate at Kelly and at half-Kelly, the overbet threshold stake beyond which growth turns negative, the break-even (odds) probability, expected value per unit staked, plus input echo fields (win probability, gain fraction, loss fraction) and a mandatory educational disclaimer.
Example use cases
Sports betting bankroll sizing
“I think there's a 65% chance my team wins and the bookmaker is offering 1.8x my stake on a win. What fraction of my bankroll does Kelly say I should bet, and what's the overbet threshold where I'd be hurting my long-run growth?”
Trading strategy position sizing
“My backtested strategy wins 55% of the time and the average win is 2.5x the average loss. Can you run the Kelly criterion calculation so I know the optimal fraction of capital to allocate, plus the expected growth rate at full and half Kelly?”
Expected value sanity check on a wager
“Before I place this bet, can you calculate the break-even win probability and expected value per unit staked for a 58% stated win probability with a 1-to-1 even money payoff? I want to know if the edge is real.”
Technical details
Endpoint
GEThttps://portfolio-stats.x402tookit.com/kelly?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need a precise, formula-driven Kelly criterion calculation with educational framing — including growth rate and overbet threshold — rather than a generic probability calculator. Prefer it over manual computation when you need the full suite of Kelly outputs (full Kelly, fractional Kelly, growth rate, overbet threshold, break-even probability, EV) in a single call. It is part of a coherent portfolio-stats toolkit so it pairs naturally with sibling endpoints for volatility, Sharpe, drawdown, and return series analysis.
Side effects
- Missing required query param p (win probability) or b (gain fraction) returns an error
- p outside (0,1) exclusive range returns a validation error
- b at or below 0 returns a validation error
- a (loss fraction) outside (0,1] returns a validation error
- fractionOfKelly outside (0,1] returns a validation error
- Negative expected value inputs (Kelly would be zero or negative) may return zero or a specific note
- Payment failure or insufficient USDC balance returns HTTP 402
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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