# Wintergreen Position Size Calculator

> Wintergreen Position Size Calculator is a paid API for AI agents from x402.wintergreen.uk, paid per call via x402, $0.001/call, status down (last checked 2026-09-15).

Calculates optimal position sizing for a crypto trade given entry price, stop loss, capital, and risk percentage using Kelly-informed risk management.

## Facts

- Endpoint: GET https://x402.wintergreen.uk/api/v1/position/calculate
- Price: $0.001/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/wintergreen-position-size-calculator-0619b7e0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0QY1gL-YnnIUp1Gs_Iofd

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 wintergreen-position-size-calculator-0619b7e0
```

Example prompt: I'm entering a BTC trade at $65,000 with a stop at $63,500, I have $10,000 in capital and want to risk 1% — what's my position size?

## When to prefer this

Choose this endpoint when an AI agent needs to compute a risk-adjusted position size for a crypto trade in real time, especially within Hyperliquid or similar perpetuals workflows. Prefer it over generic calculators when the agent is operating within the x402 micropayment ecosystem and needs a lightweight, single-call computation priced at $0.001 USDC per call.

## Known failure modes

- Missing required parameters (entry, stop, capital, risk_pct) return error
- HTTP 402 if payment header not included or USDC authorization fails
- Invalid parameter types (non-numeric values) cause schema validation errors
- Stop price equal to entry price causes division-by-zero or undefined result
- Negative or zero capital/risk values may produce nonsensical output

## How this service works

Payment-gated crypto trading intelligence for AI agents.
    
## Categories
- **Hyperliquid Signals**: Real-time funding divergence, lead-lag correlation, liquidation clusters, session volume area levels
- **Quant Methodology**: Backtesting walk-forward validation, strategy generation with kill battery (19 rules), risk management with Kelly sizing, regime detection, execution frameworks, agent orchestration
- **Market Insights**: 22 crypto microstructure observations — funding, liquidation, orderbook, regime, flow, anomaly
- **Power Markets**: ERCOT field guide, merit-order model, duck curve analysis
- **Career Guides**: Firefighter oral board prep, medical coding, ATSA, contractor estimating
- **Trust Scoring**: x402 endpoint verification, P2D badges

## Payment
All paid endpoints return HTTP 402 with USDC on Base (eip155:8453). 
Sign EIP-712 TransferWithAuthorization and retry with X-PAYMENT header.
PayTo: 0xAe9834d71F1Bd989A0dc17593451af823E31CeeD

## Output

Returns a computed position size (number of units or contracts to trade) given the entry price, stop loss level, total capital, and desired risk percentage, applying quantitative risk management logic to keep losses bounded to the specified risk amount.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "stop": {
   "type": "number"
  },
  "entry": {
   "type": "number"
  },
  "capital": {
   "type": "number"
  },
  "risk_pct": {
   "type": "number"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/wintergreen-position-size-calculator-0619b7e0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.wintergreen.uk](https://www.zero.xyz/host/x402.wintergreen.uk/llms.txt)