Pyth Is the Data Source for Kalshi's Midterms Index

The 2026 midterms now have a single number, and Pyth calculates it.
KPOW is Kalshi's index tracking the balance of political power in America. KPOW Midterms separates out the 2026 Midterm races from the rest of the index.
Kalshi, a CFTC-regulated exchange, has listed contracts on the Kalshi American Power Index – Midterms (KPOW Midterms). In its October 27 filing with the CFTC, Kalshi names Pyth as the index's Source Agency. Pyth calculates and publishes every KPOW Midterms value, and every contract on the index settles by reference to the values Pyth publishes.
You can follow KPOW Midterms live on the Pyth Terminal.
One Number For the Midterms
KPOW Midterms combines 13 Kalshi election markets into one reading:

The index runs from −50 to +50. At −50, the market prices Democratic candidates as certain to win every weighted race; at +50, Republican candidates. One point equals one percentage point, so +10 represents an approximately 60% weighted average implied probability of Republican victory across the included races, rather than a 60% probability in each individual race.
Each race scores 50 × (Republican price − Democratic price). The index is the weighted sum of those scores. Pyth calculates it from Kalshi's public trades and publishes a new value every 30 seconds.
Built to Settle Markets
A settlement number has to hold up when it matters most, so the methodology builds in a few safeguards.
A price check on every input. A trade more than $0.05 away from a market's last accepted price is held. It is accepted only when the price comes back, when the opposing party's market confirms the move within 60 seconds, or when both markets keep trading at the new level for five minutes.
Time-weighted settlement. Contracts don't settle on a single tick. They settle on a time-weighted average of the index over the 15 minutes before each settlement time. For some Election Day contracts, Kalshi can specify a 60-second window instead.
Versioned, never restated. Every methodology change is released as a numbered version that applies only going forward. A published value is never rewritten by a later version. It can be corrected only to fix a material error, and each correction is documented.
Kalshi lists KPOW Midterms contracts at several settlement intervals, including 15-minute and hourly, through Election Day on November 3.
Only the Index Counts
The filing is explicit: a race being called, projected or certified does not by itself change a contract's value. Only the value Pyth calculates and publishes counts. When a race is decided and its market stops trading, that market keeps its last accepted price and the index keeps running.
A Separate Calculation Agent
The filing splits the two jobs. Kalshi runs the exchange, the underlying markets and the contracts. Pyth independently constructs the index and publishes every value the contracts settle.