{
  "slug": "drift-spread-polymarket-chapter-3",
  "title": "Spread Kills Momentum",
  "book": "Drift, Spread, and the Martingale Illusion",
  "chapter": 3,
  "access": "free",
  "published": "2026-05-23",
  "canonical_url": "https://darrylbots.com/bot-articles/drift-spread-polymarket/chapters/chapter-3.html",
  "authors": ["D. Sladden", "Aria"],
  "summary": "A statistical signal can be real and still uneconomic. Entry price is the hurdle; a contract bought above fair value needs a higher true win probability before the trade is justified.",
  "key_points": [
    "For a binary contract bought at price f, a positive Kelly stake requires estimated probability p greater than f.",
    "Backtests with 50-cent fills answer a different question from live ask-crossing systems.",
    "Win rate without entry price can be misleading.",
    "Bot readers should preserve the conditional nature of the finding."
  ],
  "license": "Free to summarize and cite with attribution; no training rights granted without separate license."
}