2026 MidtermsEvery figure as of Sep 27, 2:39 AM ET

ConstructedStale

The market-implied chance that Democrats control the Senate in the next Congress. Democrats need 51 seats, because the vice president, a Republican, breaks 50–50 ties. Each contract's own rules decide independents, runoffs and ties.

Equal-weight average of two venues, each priced at the midpoint of its bid and ask.
Kalshi 62.5% (constructed). Kalshi has no single Senate-control contract, so we add its two balance-of-power contracts in which Democrats win the Senate: D House + D Senate (61.5¢) and R House + D Senate (0.95¢).
Polymarket 62.5%, from its Senate-control contract.
Average: 62.5%, shown as 62%.

Quote type: Midpoint of bid and ask. Cited as: “Prediction markets give Democrats a 62% chance of winning control of the Senate” (average of Kalshi and Polymarket via DeFi Rate).

History: average of Kalshi (constructed) and Polymarket daily close, 2026-05-27 to 2026-09-27 (124 rows). Daily closing average of Kalshi (constructed) and Polymarket. The last point is today's 2:39 AM observation. Full history (CSV)

Stale

The market-implied chance that Democrats win a House majority (218 seats) in the 2026 election, under each contract's settlement rules.

Equal-weight average of two venues' House-control contracts, each priced at the midpoint of its bid and ask: Kalshi 91.75% and Polymarket 92.5%. Average: 92.1%, shown as 92%.

Quote type: Midpoint of bid and ask. Cited as: “Prediction markets give Democrats a 92% chance of winning the House” (average of Kalshi and Polymarket via DeFi Rate).

History: Kalshi daily close, 2026-05-27 to 2026-09-27 (124 rows). Kalshi daily close. The 7-day change for the House is measured on Kalshi alone. Full history (CSV)

ConstructedSingle venueStale

The market-implied chance that Democrats control the Senate in the next Congress. Democrats need 51 seats, because the vice president, a Republican, breaks 50–50 ties. Each contract's own rules decide independents, runoffs and ties.

Kalshi 62.5% (constructed). Kalshi has no single Senate-control contract, so we add its two balance-of-power contracts in which Democrats win the Senate: D House + D Senate (61.5¢) and R House + D Senate (0.95¢).

Quote type: Midpoint of bid and ask. Cited as: “Kalshi's prices give Democrats a 62% chance of winning control of the Senate” (Kalshi (constructed from two contracts) via DeFi Rate).

History: Kalshi (constructed) daily close, 2026-05-27 to 2026-09-27 (124 rows). Kalshi daily close for the two-contract bundle. Full history (CSV)

Single venue

The market-implied chance that Democrats control the Senate in the next Congress. Democrats need 51 seats, because the vice president, a Republican, breaks 50–50 ties. Each contract's own rules decide independents, runoffs and ties.

Polymarket 62.5%, from its Senate-control contract.

Quote type: Midpoint of bid and ask. Cited as: “Polymarket gives Democrats a 63% chance of winning control of the Senate” (Polymarket via DeFi Rate).

History: Polymarket daily close, 2026-05-27 to 2026-09-27 (124 rows). Polymarket daily close. Full history (CSV)

Stale

The chance Republicans keep both the House and the Senate.

Average of Kalshi's R House + R Senate contract (7.75¢) and Polymarket's matching contract (7.5¢). These two contracts ask the same question, so this is a like-for-like comparison.

Quote type: Midpoint of bid and ask. Cited as: “Markets give Republicans a 8% chance of keeping both chambers” (average of Kalshi and Polymarket via DeFi Rate).

What the 35 Kalshi state-race prices imply for Senate control, if every race were independent of the others. This is DeFi Rate's calculation, not a market price.

We treat each state's Democratic price as a probability, combine all 35 races assuming they are independent, and add the 34 Democratic seats not up this year. Real races move together (a good night in Ohio usually means a good night in Texas), so this overstates how predictable the total is.

Quote type: Midpoint of bid and ask (Kalshi state contracts). Cited as: “The 35 state races imply a 65% Democratic chance under an independence assumption” (DeFi Rate calculation from Kalshi state prices via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Rhode Island.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 99% chance in the Rhode Island Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Delaware.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 99% chance in the Delaware Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Massachusetts.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 99% chance in the Massachusetts Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Colorado.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 99% chance in the Colorado Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Virginia.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 98% chance in the Virginia Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in New Jersey.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 98% chance in the New Jersey Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Illinois.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 98% chance in the Illinois Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Oregon.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 98% chance in the Oregon Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in New Mexico.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 98% chance in the New Mexico Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Georgia (Ossoff (D)).

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 94% chance in the Georgia Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in North Carolina (Cooper (D)).

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 94% chance in the North Carolina Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Minnesota.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 90% chance in the Minnesota Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in New Hampshire (Pappas (D)).

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 86% chance in the New Hampshire Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Michigan (El-Sayed (D) vs. Rogers (R)).

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 72% chance in the Michigan Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Alaska (Peltola (D) vs. Sullivan (R)).

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 71% chance in the Alaska Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Maine (Jackson (D) vs. Collins (R)).

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 61% chance in the Maine Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Texas (Talarico (D) vs. Paxton (R)).

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 61% chance in the Texas Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Ohio (special) (Brown (D) vs. Husted (R)).

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 58% chance in the Ohio (special) Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Iowa (Turek (D) vs. Hinson (R)).

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 44% chance in the Iowa Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Kansas.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 31% chance in the Kansas Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in South Carolina.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 14% chance in the South Carolina Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Mississippi.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 10% chance in the Mississippi Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Florida (special).

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 10% chance in the Florida (special) Senate race” (Kalshi via DeFi Rate).

Single venue

The chance the Democratic candidate wins the 2026 Senate race in Louisiana.

Kalshi only: every state race on this page is priced from Kalshi's contract. Price is the midpoint of Kalshi's bid and ask.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 8% chance in the Louisiana Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Arkansas.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 7% chance in the Arkansas Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Kentucky.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 5% chance in the Kentucky Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Alabama.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 4% chance in the Alabama Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in West Virginia.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 2% chance in the West Virginia Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Tennessee.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 2% chance in the Tennessee Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Wyoming.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 2% chance in the Wyoming Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Montana.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 2% chance in the Montana Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Oklahoma.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a 2% chance in the Oklahoma Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in Idaho.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a <1% chance in the Idaho Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance the Democratic candidate wins the 2026 Senate race in South Dakota.

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is the midpoint of its bid and ask when last observed, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives Democrats a <1% chance in the South Dakota Senate race” (Kalshi via DeFi Rate).

Single venueStale

The chance a Democrat wins the 2026 Senate race in Nebraska. The race is Osborn (I) vs. Ricketts (R), so this contract’s “No” side pays if the independent or the Republican wins. It isn’t a bet on the Republican, and we don’t label it “Buy GOP.”

Kalshi only: every state race on this page is priced from Kalshi's contract. Kalshi's quote is stale, so the price is its last trade, and it isn't offered as a price to buy.

Quote type: Midpoint of bid and ask. Cited as: “Kalshi gives a Democrat a <1% chance in the Nebraska Senate race, where no Democrat is the main challenger (Osborn (I) vs. Ricketts (R))” (Kalshi via DeFi Rate).