# DarrylBots Agent Article – Position Sizing Chapter (Drift, Spread & Martingale Illusion Series)

> DarrylBots Agent Article – Position Sizing Chapter (Drift, Spread & Martingale Illusion Series) is a paid API for AI agents from darrylbots.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Returns a paid early-access chapter on position sizing for prediction-market trading bots, including agent-ready takeaways on Kelly criterion, hard caps, and stake reasoning codes.

## Facts

- Endpoint: GET https://darrylbots.com/api/agent-article-position-sizing
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/darrylbots-agent-article-position-sizing-chapter-drift-spread-e6c674e1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VAcTaomzArH-xr82A2H8T

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 darrylbots-agent-article-position-sizing-chapter-drift-spread-e6c674e1
```

Example prompt: Fetch the DarrylBots paid chapter on position sizing without superstition from the Drift, Spread, and Martingale Illusion series — I want the agent takeaways on Kelly criterion haircuts, hard caps, and stake reason codes for my Polymarket trading bot.

## When to prefer this

Choose this endpoint when an AI trading agent or quant bot needs structured, agent-readable guidance on prediction-market position sizing, specifically Kelly criterion application with hard caps and auditable stake logic. Prefer over generic finance APIs when you need opinionated, bot-friendly takeaways rather than raw market data, and when your agent operates on Polymarket or similar binary markets and needs a principled, superstition-free sizing framework.

## Known failure modes

- Payment not completed or insufficient USDC balance – returns 402 Payment Required with payment instructions
- Invalid or malformed properties parameter – may return empty or error response
- Chapter content URL unavailable or server error – returns 5xx with no content
- Network or Base chain payment verification failure – payment not confirmed, content not unlocked

## How this service works

Darrylbots paid early access: Drift, Spread, and the Martingale Illusion, Chapter 6

## Output

Returns a JSON payload containing the article slug, title, series name, paid early-access status, chapter summary, a list of agent-readable takeaways (covering entry price constraints, Kelly ceiling haircuts, loss-state reasoning, zero-size decisions, and reason codes), a content URL to the full JSON chapter, a preview HTML URL, and x402 payment metadata including asset address, pay-to address, and facilitator details.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "article": {
   "slug": "drift-spread-polymarket-chapter-6",
   "price": {
    "amount": "0.001",
    "network": "Base",
    "currency": "USDC",
    "amount_atomic": "1000",
    "network_caip2": "eip155:8453"
   },
   "title": "Position Sizing Without Superstition",
   "series": "Drift, Spread, and the Martingale Illusion",
   "status": "paid_early_access",
   "payment": {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "pay_to": "0x0BF63F37b0f512839C001548dc66a6A99Bfc019B",
    "scheme": "exact",
    "protocol": "x402",
    "facilitator": "https://api.cdp.coinbase.com/platform/v2/x402"
   },
   "content_url": "https://darrylbots.com/bot-articles/drift-spread-polymarket/data/chapter-6.json",
   "preview_url": "https://darrylbots.com/bot-articles/drift-spread-polymarket/chapters/chapter-6.html"
  },
  "chapter": {
   "id": "drift-spread-polymarket-chapter-6",
   "title": "Position Sizing Without Superstition",
   "chapter": 6,
   "summary": "A paid chapter on converting prediction-market confidence into capped, auditable stakes without confusing aggression for edge.",
   "series_title": "Drift, Spread, and the Martingale Illusion",
   "agent_takeaways": [
    "Entry price is the first sizing constraint in binary markets.",
    "Kelly can inform a ceiling, but production bots need haircuts and hard caps.",
    "Previous losses do not create edge; they only update state.",
    "A zero-size decision is an active risk control, not inactivity.",
    "Every paid-call payload should expose reason codes for stake, cap, and stop condition."
   ]
  },
  "purchased": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/darrylbots-agent-article-position-sizing-chapter-drift-spread-e6c674e1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from darrylbots.com](https://www.zero.xyz/host/darrylbots.com/llms.txt)