| name | prediction_markets |
| description | How to read prediction markets (Kalshi, Polymarket) — price-as-probability, resolution rules before any comparison, fees/spread, and comparing exchange contracts to book odds honestly. |
| triggers | ["prediction market","kalshi","polymarket","event contract","binary contract","resolution","settlement"] |
Prediction markets
Prediction markets (Kalshi, Polymarket) trade binary/event contracts that pay 1
unit if an outcome happens and 0 if it doesn't. The contract's price therefore is
the market's probability: a contract trading at 0.62 means a 62% implied chance.
Read the resolution rules first
The single biggest mistake is comparing two markets that resolve differently. Before
any comparison, read market_detail for the exact question, the settlement source,
and the expiry. "Team X wins the title" and "Team X wins the final" are different
contracts. If the book's market and the prediction market don't resolve on the same
condition, say so and stop — the comparison is invalid.
Price → probability
- Best bid / best ask (
market_prices) bracket the fair value; use the mid for a
point estimate and note the spread (wide spread = thin/uncertain market).
- Do not vig-remove a single binary contract price — it's already a probability.
The exchange takes a fee on settlement, not a two-sided overround like a book.
The exchange-vs-book edge
This is the high-value play and why this agent exists:
- Take the contract's implied probability (prediction market).
- Take the SAME outcome at the sportsbooks (
find_fixture → best_prices), and
vig_removal the book market to a fair probability.
- Compare. A meaningful gap means one side is mispriced relative to the other —
report which side is the value, the size of the gap, and the venues. Liquidity and
the fee/withdrawal frictions on each venue determine whether it's actually takeable.
Honesty
Surface the probabilities, the gap, and the caveats (thin liquidity, resolution-rule
mismatch, fees). The user decides and acts; this agent never trades or bets.
