$742.4 million
in independent expenditures in Senate races reported to the FEC in 24- and 48-hour notices, for spending dated Oct. 1 to Oct. 23, 2026. 67% of it went to the 7 races where the market favorite is priced under 70%.
FEC filings and Kalshi/Polymarket market data, pulled Oct 23, 2026, 8:42 AM ET. Updated daily.
By Arthur Angelo, PredictionScout Research · Updated Oct 23, 2026, 8:42 AM ET
$742.4 millionlate outside spending
3,698FEC notices
67%in toss-up races
34states with spending
Key findings
- 67% of late outside spending is in 7 races that Kalshi and Polymarket price as toss-ups (favorite under 70%, average of the two exchanges, snapshot of 2026-10-23). Ohio $176.6 million; Texas $148.0 million; Michigan $99.5 million lead all states.
- Spending by tier: toss-up races $499.8 million across 7 states; leaning races $178.9 million across 5 states; not close races $63.6 million across 20 states; $34,750 in 2 states with no listed market.
- Support vs oppose, as filed: 23% of the total was reported as supporting a candidate and 77% as opposing one, across 3,698 notices from 240 committees.
- Largest spenders: Winsenate $110.1 million; Slf Pac $87.0 million; Texas Pac $49.6 million.
- Largest single notice: $21.6 million by Texas Pac opposing James Talarico (D-TX), dated Oct. 20.
Late outside spending by Senate race
Independent expenditures with dates from Oct. 1 to Oct. 23, from 24- and 48-hour notices filed with the Federal Election Commission. “For” and “against” follow the support/oppose box each committee checked. Market favorite and price: average of Kalshi and Polymarket in the 2026-10-23 snapshot.
| Race | Market favorite | Outside spending | Top candidates targeted |
|---|---|---|---|
| Ohio | Sherrod Brown (D) 70% | $176.6 million | Jon Husted (R): for $28.7 million / against $62.5 million Sherrod Brown (D): for $7.5 million / against $73.1 million William Redpath (L): for $1.7 million Gregory Lee Levy (I): for $1.3 million |
| Texas | James Talarico (D) 66% | $148.0 million | James Talarico (D): for $13.1 million / against $90.5 million Kenneth Warren Paxton Jr. (R): against $20.9 million Warren Kenneth Paxton Jr. (R): for $6.8 million / against $11.5 million Warren Paxton Jr. (R): against $3.6 million |
| Michigan | Abdul El-Sayed (D) 70% | $99.5 million | Abdul El-Sayed (D): for $17.8 million / against $47.1 million Michael J. Rogers (R): for $13.6 million / against $4.9 million Michael Rogers (R): against $13.5 million Abdul El-Sayed (?): for $856,908 / against $220,500 |
| Iowa | Ashley Hinson (R) 57% | $74.0 million | Ashley Hinson Arenholz (R): for $7.1 million / against $33.2 million Joshua Turek (D): for $8.6 million / against $21.4 million Josh Turek (D): for $2.3 million / against $915,419 Ashley Hinson (R): for $13,591 / against $174,954 |
| Maine | Troy Jackson (D) 66% | $46.5 million | Troy Dale Jackson (D): for $1.4 million / against $23.2 million Susan Collins (R): for $147,560 / against $15.9 million Susan M. Collins (R): for $2.0 million / against $2.0 million Troy Jackson (?): for $501,882 / against $946,500 |
| Alaska | Mary Peltola (D) 75% | $38.0 million | Dan Sullivan (R): for $4.3 million / against $17.4 million Mary Peltola (D): for $3.1 million / against $11.8 million Gerald L. (jerry) Heikes (R): for $1.4 million Mary Mary Peltola (D): against $8,377 |
| Kansas | Roger Marshall (R) 62% | $38.0 million | Adam Hamilton (D): for $2.8 million / against $13.1 million Roger W. Marshall (R): for $2.0 million / against $13.5 million Roger Marshall (R): against $5.6 million Adam Hamilton (?): against $1.0 million |
| Nebraska | Pete Ricketts (R) 74% | $33.7 million | Dan Osborn (I): for $6.1 million / against $14.7 million Pete Ricketts (R): for $429,659 / against $12.3 million Pete Ricketts (?): for $47,119 Dan Osborn (?): for $729 |
| New Hampshire | Chris Pappas (D) 90% | $26.2 million | John E. Sununu (R): for $3.2 million / against $10.3 million Chris Pappas (D): for $1.0 million / against $11.5 million Edmond Laplante (RNC): for $105,736 John E. Sununu (?): for $57,441 |
| South Carolina | Darline Graham Nordone (R) 41% | $16.5 million | Annie Andrews (D): for $1.7 million / against $7.0 million Darline Graham (R): for $3.3 million / against $4.3 million Annie Andrews (?): against $46,597 Darline Graham (?): for $46,597 |
| Georgia | Jon Ossoff (D) 96% | $11.9 million | T. Jonathan Ossoff (D): for $2.4 million / against $2.0 million Michael A. Collins Jr. (R): for $133,212 / against $2.9 million T. Jonathan Ossoff (?): for $1.9 million Mike Collins (R): against $1.0 million |
| Florida | Ashley Moody (R) 91% | $11.8 million | Angela Nixon (D): for $3.3 million / against $3.0 million Ashley Moody (R): for $1.7 million / against $3.4 million Angie Nixon (?): for $365,776 Ashley Moody (?): against $73,221 |
| Mississippi | Cindy Hyde-Smith (R) 89% | $4.9 million | Scott Colom (D): for $2.6 million Cindy Hyde-Smith (R): for $21,393 / against $2.3 million |
| North Carolina | Roy Cooper (D) 96% | $4.0 million | Roy Cooper (D): for $2.1 million / against $1.4 million Michael Whatley (R): for $123,075 / against $150,511 Roy Cooper (?): for $148,386 Roy Asberry Cooper III (D): for $15,192 |
| Minnesota | Peggy Flanagan (D) 86% | $2.8 million | Margaret Flanagan (DFL): for $1.5 million / against $1.2 million Michele Tafoya (R): for $25,200 / against $71,000 Peggy Flanagan (DFL): for $16,165 Peter Allen Stauber (R): against $200 |
| Montana | Kurt Alme (R) 93% | $2.5 million | Seth Bodnar (I): for $1.8 million Kurt Alme (R): for $608,302 / against $12,376 Alani Ines Bankhead (D): against $113,687 |
| South Dakota | Mike Rounds (R) 95% | $2.0 million | Mike Rounds (R): against $1.1 million Brian Bengs (I): for $654,836 / against $225,475 |
| Louisiana | Julia Letlow (R) 93% | $1.6 million | Blake Miguez (R): against $1.1 million Julia Letlow (R): for $465,001 |
| Kentucky | Andy Barr (R) 97% | $1.3 million | Garland Andy Barr (R): for $1.2 million Andy Rep. Barr IV (?): for $22,314 Charles Booker (D): for $1,114 |
| Arkansas | Tom Cotton (R) 95% | $1.2 million | Hallie Shoffner (D): against $1.2 million |
| Alabama | Barry Moore (R) 99% | $286,582 | Felix Barry Moore (R): for $286,582 |
| New Mexico | Ben Ray Luján (D) 96% | $274,429 | Ben Ray Lujan (D): for $274,429 |
| Delaware | Democrat 49% | $231,764 | Christopher A. Coons (D): for $231,764 |
| Massachusetts | Ed Markey (D) 98% | $230,000 | John Deaton (R): for $230,000 |
| Oklahoma | Kevin Hern (R) 97% | $186,556 | Kevin Hern (R): for $186,556 |
| Idaho | Jim Risch (R) 96% | $105,000 | Todd Baker Achilles (I): for $105,000 |
| West Virginia | Shelley Moore Capito (R) 98% | $49,975 | Shelley Moore Capito (R): for $49,975 |
| Virginia | Mark Warner (D) 98% | $33,089 | Mark Warner (D): for $31,518 Douglas Ollivant (R): for $1,571 |
| NB | no market | $31,680 | Dan Osborn (I): for $31,680 |
| Wyoming | Harriet Hageman (R) 99% | $21,585 | Harriet Hageman (R): for $21,585 |
| Tennessee | Bill Hagerty (R) 96% | $21,224 | Bill Hagerty (R): for $21,224 |
| California | no market | $3,070 | T. Jonathan Ossoff (?): for $3,070 |
| New Jersey | Cory Booker (D) 97% | $1,060 | Justin Michael Ll.m Murphy (R): for $1,060 |
| Colorado | John Hickenlooper (D) 99% | $670 | John W. Hickenlooper (D): for $670 |
Biggest spenders
| Committee | Late Senate spending |
|---|---|
| WINSENATE | $110.1 million |
| SLF PAC | $87.0 million |
| TEXAS PAC | $49.6 million |
| DEFEND AMERICAN JOBS | $42.2 million |
| AMERICANS FOR PROSPERITY ACTION, INC. (AFP ACTION) DBA CVA ACTION AND DBA LIBRE ACTION | $39.0 million |
| AMERICA PAC | $37.4 million |
| LOWER COSTS NOW | $34.0 million |
| NO GOING BACK PAC INC. | $26.4 million |
| AB PAC | $22.9 million |
| DUTY AND COUNTRY | $15.7 million |
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By race (CSV)By committee and candidate (CSV)
Totals by race, and by committee and candidate. Amounts are as reported to the FEC; no market price histories are included. Free to reuse under CC BY 4.0 with a link back to this page.
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Methodology
- Spending. Independent expenditures in 2026 Senate races from the FEC’s OpenFEC API (Schedule E), limited to 24- and 48-hour notices, the most recent version of each amended item, and expenditure dates from Oct. 1 to the update date (entries with impossible future dates are dropped). Memo subtotals are excluded, and an item re-filed in a second notice with the same transaction ID, amount and date is counted once. These notices are filed within a day or two, so they are the freshest view; the same spending later reappears in regular reports, which we do not add, to avoid double counting.
- Support and oppose. Taken exactly as each committee reported it. Spending against one candidate is not reassigned to an opponent.
- Markets. The favorite and its price come from Kalshi and Polymarket in our daily midterm snapshot (average of the two where both list the race). Tiers: under 70%, 70–89% and 90% or more.
- Limits. Notices can be amended or corrected, and some committees file late; spending reported only in regular reports (for example, under the $10,000 48-hour threshold before the final 20 days) is missing; party coordinated spending and candidate spending are not independent expenditures and are excluded; a market price is a crowd estimate, not a forecast by PredictionScout. Nothing here is investment advice. Last run: Oct 23, 2026, 8:42 AM ET.
Cite this research
Suggested citation: PredictionScout. (2026, October 23). Senate Outside Spending vs Prediction Market Odds: Where Late Money Is Going. https://predictionscout.com/research/senate-outside-spending-vs-prediction-market-odds/
For a chart or news story: “Source: PredictionScout analysis of public exchange data (https://predictionscout.com/research/senate-outside-spending-vs-prediction-market-odds/)”
The data and charts on this page are free to reuse under CC BY 4.0 with a link back to this page. Spending: Federal Election Commission. Market data: Kalshi, Polymarket.
Data sources: prices and volumes come from the public APIs of Kalshi and Polymarket, with campaign finance data from the Federal Election Commission. All trademarks belong to their owners. PredictionScout is independent and not affiliated with any exchange. Nothing here is investment, betting, or legal advice.
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