Use Jev to evaluate a precisely defined market outcome, compare that judgment with the price you can actually pay, then submit your purchase on Polymarket. Jev supplies an assessment; your trading interface handles the order.
The Jev for Polymarket tool lets you explore three recorded market examples, prepare a request and compare manually entered probabilities with prices. It does not call Jev, connect a wallet or place orders. The examples preserve September 20, 2026 snapshots from the reference demo, not live quotes or predictions.
1. Start with the exact market and its rules
Choose the particular outcome and deadline you want to evaluate. Record the full resolution rules, timezone, evidence source and exceptions. An event can contain several binary markets, so an event title alone does not identify the shares you intend to buy. Polymarket market structure.
For the reference site's Bitcoin case, the question concerns touching $100,000 before a deadline. That differs from closing above $100,000 on the final day. Reopen the linked original market and check its current rules before using the example.
2. Choose the matching Jev question type
| Question | Jev type | Reference example |
|---|---|---|
| Will one proposition be true? | Noul | Bitcoin reaching the specified threshold by the selected deadline |
| Which mutually exclusive outcome occurs? | Choice | Anthropic listing on NASDAQ, NYSE or Other |
| Which ordered category applies? | Score | The October 2026 Fed decision, from a large cut to a large increase |
Noul returns a value for a binary judgment. Choice returns probabilities for named alternatives. Score uses ordered criteria and returns their probabilities plus a weighted level score. Noul, Choice, Score.
Preserve the source rules when defining categories. The reference's Anthropic “Other” includes some scenarios with no qualifying listing by the deadline. Its five Fed categories have an order, but their index average is neither a basis-point forecast nor the probability of a particular outcome. These case definitions come from the reference demo; use its original-market links to check the full rules.
3. Supply evidence and obtain a real response
Prepare a Jev request containing the market rules and dated evidence in state, and the matching question in questions. Keep evidence consistent with the decision time. Supplying a market URL alone is not a substitute for collecting the facts to evaluate.
The local tool previews a request without sending it. Supply your own evidence and obtain a real response through your integration before presenting a comparison as model-based. See the existing Jev trading workflow for request handling. A model estimate is not proof that its forecasts are calibrated for this market.
4. Compare the selected outcome with its executable price
Keep three quantities separate: the model estimate, the site's displayed market probability, and the price available for your order size. Polymarket's displayed probability can use the bid/ask midpoint or last trade, so it is not necessarily your purchase price. Price explanation.
For a standard binary share paying $1 if correct and $0 otherwise, a teaching calculation is:
estimated net value per share = p − purchase price − costs per share
For example, suppose—not as a real Jev result—that p = 0.60, the purchase price is $0.55, and estimated costs are $0.01 per share. The result is $0.04 per share under those assumptions. It is an expected-value estimate, not a promised return. If the outcome loses, the purchase cost can be lost. Use the specific market's payout rules and current fees.
5. Place and verify the purchase on Polymarket
- Open the original market and complete Polymarket's account and funding steps applicable to you.
- Check the exact submarket, deadline and YES/NO side against your Jev question.
- Inspect available liquidity and the order preview. Choose your amount and maximum acceptable price.
- If using a limit order, set the price and share quantity, then review the total before submitting.
- Check orders and positions afterward. An accepted order may be unfilled or partly filled; submission alone does not establish the intended position.
Limit orders can fill partially. Review open orders on the market or Portfolio page, and cancel unwanted outstanding quantities. Limit-order guide.
6. Keep a record and follow settlement
Save the rules, evidence time, model response and actual fills. Reassess when facts change. Final settlement follows the original market rules rather than Jev's output. This makes it possible to compare forecast quality and execution costs later without confusing model estimates, screenshots and realized results.