# Kelly Criterion Binary Fraction Calculator

> Kelly Criterion Binary Fraction Calculator is a paid API for AI agents from handel.halowerk.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-21).

Computes the binary Kelly fraction (optimal bet size as a proportion of capital) given a win probability and payoff ratio, with no market data or brokerage access.

## Facts

- Endpoint: POST https://handel.halowerk.com/v1/rechner/kelly?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/kelly-criterion-binary-fraction-calculator-bbdb3b7f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hJCwKXFc-So09MHmrJBou

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability kelly-criterion-binary-fraction-calculator-bbdb3b7f -d '<json body>'
```

Example prompt: Calculate the Kelly fraction for a binary bet where I have a 55% chance of winning and the payoff ratio is 1.8.

## When to prefer this

Use this endpoint when you need a pure, stateless computation of the binary Kelly fraction with no side effects, no external data fetching, and no broker integration. Prefer it over general-purpose formula evaluators when you want a dedicated, validated implementation of Kelly criterion math. Not suitable if you need continuous Kelly variants, fractional Kelly presets, or market data lookups.

## Known failure modes

- win_probability outside [0,1] — validation error
- payoff_ratio below 1e-12 or above 1e12 — validation error
- missing required fields — request rejected
- negative Kelly fraction returned as-is (not reinterpreted as zero) — callers must handle edge cases themselves

## How this service works

Binärer Kelly-Anteil als Modellzahl. Unbegrenztes binäres Modell, konstante unabhängige Treffer; negative Ergebnisse werden nicht zu einem Einsatzvorschlag umgedeutet. Alle Zahlen, Kurse und Vorgaben liefert der Aufrufer. Keine eigenen Kursdaten, kein Brokerzugriff, keine Ausführung. Rechenwerkzeug, keine Anlageberatung, keine Empfehlung.

## Output

A numeric Kelly fraction (between 0 and 1, or negative if the bet is unfavorable, returned as-is without reinterpretation) representing the theoretically optimal proportion of capital to allocate to a single binary bet given the supplied win probability and payoff ratio.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "payoff_ratio": {
   "type": "number",
   "maximum": 1000000000000,
   "minimum": 1e-12
  },
  "win_probability": {
   "type": "number",
   "maximum": 1,
   "minimum": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/kelly-criterion-binary-fraction-calculator-bbdb3b7f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from handel.halowerk.com](https://www.zero.xyz/host/handel.halowerk.com/llms.txt)