Understand what you’re trading.
Splitrule brings prediction-market prices, trading costs, and changes to contract rules into one research workbench. Every number shows its source.
Browse without an account. Splitrule never places orders.
- source
- Splitrule’s stored Polymarket US catalogue.
- cadence
- Refreshed every 5 minutes. Marked stale after 15 minutes.
- coverage
- A partial refresh shows its count as a minimum.
- source
- Splitrule’s daily cross-listing check. Counts only, no market names.
- cadence
- Daily at 13:20 UTC. Marked stale after 72 hours.
- coverage
- After a live read, the card adds how many published rows have a confirmed match, and the capture.
A confirmed match names one question on two venues. It does not prove equal settlement terms or a hedge. A missing verdict is not approval.
See what a price leaves out.
Worked example · Polymarket US
One market, read on Sep 22, 2026
Buying at the 32.00¢ ask and paying the taker fee puts the conservative breakeven at 34.01¢. The outcome must be at least that likely.
Quotes from a two-sided politics contract on Polymarket US. This dated example does not change with new captures.
- Bid
- 31.00¢
- Ask
- 32.00¢
Breakeven (long)34.01¢[33.01¢, 34.01¢]Ask + taker fee · conservative bound
Cost to cross vs midpoint2.49¢[1.49¢, 2.49¢]Half the spread + fee · sell at the bid
One fill is assumed: a per-contract floor, not a worst case. Quotes carry no executable size. Check the venue’s book before trading.
Calculation & receipt
- Bid / ask
- 0.3100 / 0.3200
- Spread
- 1.00¢
- Implied p (mid)
- 31.5%
- Breakeven (long)
- 34.01¢ [33.01¢, 34.01¢]
- Midpoint after assumed exit fee
- 29.50¢ [29.50¢, 30.50¢]
- Cost to cross vs midpoint
- 2.49¢ [1.49¢, 2.49¢]
- Crossing
- sell at the bid
Schedule effective Sep 17, 2026, read from the venue’s published fee page. Dated reference, not current fee authority. The fee is rounded to the nearest cent per fill.
On a market page, each figure opens its receipt: the price source and clock, the fee schedule and its effective date, the fill assumption, and the rounding rule.
Track rule changes. Compare the facts.
Follow changes to Polymarket US market rules, then compare two markets side by side with their prices, dates, and sources.
Research reports
- Fees & rulesFee schedules, rules drift and venue-page watches.
- Market datesClosings, official releases and reported open interest.Closing dates do not establish settlement or payment dates.
- StatisticsFigures with their capture dates and sources.
- A rules-edit reportA dated case study · August 13, 2026.