15 Minute Markets

Settlement Mismatch Report · free, monthly

The same question, two venues, two different payouts

Every month we grade each pair of matched markets on Kalshi, Polymarket US and global Polymarket by whether they pay the same on every outcome, from the two rules and their past settlements. This is the count. The pair-by-pair data is in the settlement-fungible universe on the Data plan.

Too little data

0 pairs settled in September 2026, fewer than the 50 the report needs, so it publishes counts and no percentages.

0matched pairs graded in September 2026/f/mm-202609-pairs-a417796798
Not publishedgraded C or D: a clause that can pay differentlyNo permalink for this figure
Not publishedof matched contracts traded sat in pairs graded C or DNo permalink for this figure
0pairs that actually settled differently/f/mm-202609-disagreed-16214a278b

Pairs by grade

A0
Same source, window and outcomes; past settlements agree
B0
Same outcome, different source or window; agree above 99%
C0
A clause that can pay differently, or too few settlements
D0
Paid differently in a named case

The clauses that differed most

No clause differed between graded pairs this month.

Pairs that settled differently

No matched pair settled differently in September 2026.

Counts and clauses only; no finding about any person.

Method

Grades come from a tested comparator over the two rule texts and past settlements, never from a language model. Matched volume is in contracts: the Kalshi side's listed contracts traded, from the daily catalog. A pair with no Kalshi side counts as no volume; 0 of this month's pairs had none. Every figure above has a permanent link that keeps its value when next month's report is out.

As of Oct 26, 2026.

Methods and error ratesSettlement-fungible universe (Data plan)

All months