Oct 26, 2026update
Kalshi and Polymarket back within a point on control; Kalshi's South Carolina price up 4 to 24%
The two chamber gaps that opened on October 25 narrowed. Kalshi's control contract rose a point to 63.5% and Polymarket fell 2 to 64.5%, a 1-point gap, from 4. Kalshi's seat-count market, summed at 51 seats and above, fell from 66.4% to 64.8%, now 1.3 points over control, from 3.8. Its thirteen seat contracts imply 60.5% to 61.7%, 1.8 points under control.
In the seats, Kalshi's South Carolina price went from 20% to 24% with the poll average unchanged at Graham +2.1, so the market now takes 2.5 points off the Democrat there, from 3.3 on October 24. FiftyPlusOne's October 26 reading lowered Ohio from 64.5% to 62.7%, Kansas from 51.2% to 48.7% and control from 73.5% to 72.4%; the spread between the two models on control is 18.4 points, from 19.5. Kalshi's Michigan price fell 3 points to 65.5%.
All four open entries were revised to today's board; none was opened or closed. The venue entry closes if the gap stays under 2 points on the next board, and the seat-count entry if its seat-count leg does. DDHQ's reading is still dated October 2; no newer one has been recorded since October 5.
Oct 25, 2026update
Kalshi's control price fell 3 points to 62.5%, now 4 under Polymarket and 3.8 under its own seat-count market
Kalshi's control contract went from 65.5% to 62.5% since October 24. Polymarket fell 1 point to 66.5%, so the two venues are 4 points apart on the same question, the widest gap on any board since October 2. Kalshi's seat-count market, summed at 51 seats and above, rose from 65.9% to 66.4% and now sits 3.8 points over control, from 0.4.
The thirteen Kalshi seat contracts fell less than control: Maine 3 points to 60.5%, Minnesota 2 to 83.5%, Ohio 1 to 67.5%, with Texas and Nebraska up 1 each. Together they imply 61.1% to 62.6%, a range that now contains control, after a 2.1-point gap on October 24. The models are unchanged: 54% for DDHQ, 73.5% for FiftyPlusOne.
A venue entry was opened on the Kalshi-Polymarket gap; an earlier one on the same question closed October 15. The seat-count and model-spread entries were revised to today's board. The seat-count entry stays open and closes when both legs are under 2 points on two consecutive boards. DDHQ's reading is still dated October 2; no newer one has been recorded since October 5.
Oct 24, 2026update
Kalshi's seat prices fell further than its control price; control now sits 2.1 points above them
Since October 22 Kalshi's seat contracts fell: Texas 4 points to 63.5%, Ohio, Maine and Minnesota 2 each to 68.5%, 63.5% and 85.5%, with South Carolina up 1.5 to 20.5%. Together they now imply 61.9% to 63.4% for a Democratic majority. The control contract went from 66.5% to 67.5% on October 23 and 65.5% today, so it sits 2.1 points over its parts, after 4.5 on October 23. The seat-count market, summed at 51 seats and above, fell from 68.9% to 65.9%, 0.4 points over control, from 2.4 on October 22 and 2.2 on October 23.
In Ohio and Texas the market again marks the Democrat's poll lead down, by 0.8 points on a Brown +3.9 average and 0.1 on Talarico +2.3, where on October 22 it added to both. The models are 19.5 points apart on control, 54% against 73.5%, from 21.1.
The seat-count, model-spread and red-state entries were revised to today's board. The seat-count entry stays open on both legs and closes when both are under 2 points on two consecutive boards. No entry was opened or closed. DDHQ's reading is still dated October 2; no newer one has been recorded since October 5.
Oct 22, 2026update
Kalshi's control price rose 4 points to 66.5%; its seat-count market is now 2.4 points above it
Kalshi's control contract rose from 62.5% on October 19 to 66.5%, and Polymarket's from 64.5% to 68.5%. The seat contracts rose with it: Texas 6 points to 67.5%, Ohio 5 to 70.5%, Maine 5 to 65.5%, with Iowa down 2 to 41.5%. Together they now imply 63.6% to 65.6% for a Democratic majority, so control sits 0.9 points over its parts, under 2 on all four boards since October 19. The seat-count market, summed at 51 seats and above, is 68.9%, 2.4 points over control.
In Ohio and Texas the market now adds to the Democrat's poll lead rather than marking it down: 0.3 points on a Brown +3.2 average and 0.6 on Talarico +2.3. DDHQ's model takes 3 and 1.3 off, FiftyPlusOne 0.6 and 0.8. In South Carolina the market still takes 3.9 points off, against FiftyPlusOne's 0.3. The models remain 21.1 points apart on control, 54% against 75.1%.
The seat-count, model-spread and red-state entries were revised to today's board. The seat-count entry stays open on the seat-count leg and closes if that gap is under 2 points on two consecutive boards. No entry was opened or closed. DDHQ's reading is still dated October 2; the daily reader has failed to load its page every day since October 5.
Oct 19, 2026update
Kalshi's control price is 1.9 points over its seat contracts, the first board under 2 since October 10
Kalshi's thirteen seat contracts now imply a 60.3% to 60.6% chance of a Democratic majority, from 59.5% to 59.7%, as Kansas and Maine rose 2 points each and South Carolina and Michigan 1. The control contract held at 62.5%, so it sits 1.9 points over its parts, from 2.8. The seat-count market, summed at 51 seats and above, rose from 62.3% to 63.4% and is 0.9 points over control.
Kansas is 28.8 points apart across sources: FiftyPlusOne 51.8%, Kalshi 38.5% and DDHQ 23%. In Ohio the five-aggregator poll average fell from Brown +3.5 to +3.1 as Decision Desk HQ's polling average moved from Brown +3.0 to +1.5, and the newest poll, ActiVote, has the race tied at 50; Kalshi is unchanged at 65.5%, so its markdown of Brown's lead fell to 0.5 points. In South Carolina Kalshi rose from 16.5% to 17.5% and takes 4.3 points off the Democrat, against FiftyPlusOne's 0.8.
The seat-count, model-spread and red-state entries were revised to today's board. The seat-count entry stays open and closes if the gap to the seat contracts is still under 2 points on the next board. No entry was opened. DDHQ's reading is still dated October 2.
Oct 18, 2026update
Kalshi's seat-count market is back within 0.2 points of its control price; FiftyPlusOne has Kansas at 51.4%
Kalshi's seat-count market, summed at 51 seats and above, rose from 60.4% to 62.3%, against a control contract unchanged at 62.5%. The gap between them fell from 2.1 points to 0.2, so October 17 is the only board since October 12 on which they were more than 2 points apart. The thirteen seat contracts imply 59.5% to 59.7%, and control sits 2.8 points over its parts, over 2 on every board since October 11.
FiftyPlusOne's Kansas number is 51.4%, from 46.4% on October 15, against DDHQ's 23% and Kalshi's 36.5%, so Kansas is 28.4 points apart across sources. Against a five-aggregator poll average of Hamilton +0.7, FiftyPlusOne takes 0.5 points off his lead, Kalshi 2.9 and DDHQ 5.5. FiftyPlusOne's control number is 74.9%, from 73.4% on October 15, and the models are 20.9 points apart; Kalshi is at 62.5% and Polymarket at 64.5%.
The seat-count and model-spread entries were revised to today's board; the seat-count entry stays open on the gap to the seat contracts. No entry was opened or closed. DDHQ's reading is still dated October 2.
Oct 17, 2026update
Kalshi's seat-count market slipped 2.1 points under its control price; Ohio rose 5 points with the polls unchanged
Kalshi's seat-count market, summed at 51 seats and above, fell from 61.5% on October 15 to 60.4%, while the control contract rose from 61.5% to 62.5%. That puts the seat-count market 2.1 points under control, the first board on which it sits more than 2 points below it; it had been within 2 points on the five boards from October 12 to 16. The thirteen seat contracts imply 59% to 59.6%, so control sits 2.9 points over its parts, over 2 on every board since October 11.
Kalshi's Ohio price rose from 59.5% to 62.5% on October 16 and 64.5% today, while the five-aggregator poll average moved from Brown +3.4 to +3.5. Against that average the market's markdown of Brown's lead fell from 1.8 to 1.1 points, against DDHQ's 3.3 and FiftyPlusOne's 0.9. South Carolina's spread narrowed from 21 to 19.6 points as Kalshi rose from 14.5% to 15.5%.
The seat-count and red-state entries were revised to today's board. The model-spread entry is unchanged: Kansas is 25.1 points apart and Maine 18.3, from 23.4 and 16.7, and the models are 19.2 points apart on control. No entry was opened. DDHQ's reading is still dated October 2.
Oct 15, 2026update
Kansas is 23.4 points apart across sources; Kalshi's seat-count market now matches its control price
FiftyPlusOne's Kansas number rose from 42.5% on October 12 to 46.4%, against DDHQ's 23% and Kalshi's 36.5%, so the spread there widened from 19.5 to 23.4 points. Its control number rose from 71.4% to 73.4%, and the models are 19.4 points apart; FiftyPlusOne now runs 2 points or more above DDHQ in ten of the fourteen seats, Nebraska added. Kalshi (61.5%) and Polymarket (63.5%) are unchanged since October 12.
Kalshi's seat-count market, summed at 51 seats and above, fell from 62.7% to 61.5% and now matches the control contract, after four boards within 2 points of it. The thirteen seat contracts imply 58.1% to 58.5%, so control sits 3 points over its parts, from 2.4, as the correlation implied by the four-seat joint contract eased from 0.78 to 0.72. The gap between venues has been 2 points on four boards.
The model-spread and seat-count entries were revised to today's board; the seat-count entry stays open on the control gap. The venue entry is closed. No entry was opened. The Kansas poll average on today's board rests on one aggregator, RealClearPolitics, against five on October 12, so Kansas markdowns are read against the October 12 average. DDHQ's reading is still dated October 2.
Oct 12, 2026update
Kalshi’s seat-count market back within 1.2 points of its control price; Kalshi and Polymarket 2 points apart
Kalshi’s control contract rose from 60.5% to 61.5% after three boards unchanged, and its seat-count market, summed at 51 seats and above, eased from 64.1% to 62.7%. The gap between the two narrowed from 3.6 to 1.2 points, the least since October 5. Polymarket held at 63.5%, so the gap between venues narrowed from 3 points to 2.
Kalshi’s thirteen seat contracts now imply 58.5% to 59.1%, from 58.2%, as the correlation implied by its four-seat joint contract rose from 0.71 to 0.78 with that contract at 51.5%, from 49.5%. The control contract sits 2.4 points over its parts, from 2.2.
No seat price or model reading moved 2 points or more. FiftyPlusOne’s control number is 71.4%, from 72%, and the models are 17.4 points apart. The seat-count entry was revised to today’s board and stays open; the seat-count gap closes if it stays under 2 on the next board. No entry was opened or closed. DDHQ’s reading is still dated October 2.
Oct 11, 2026update
Kalshi and Polymarket 3 points apart on Senate control; Kalshi’s control price back over its seat contracts by 2.2
Kalshi’s control contract held at 60.5% for a third board while Polymarket rose from 62.5% on October 9 to 63.5%, a 3-point gap on the same question and the widest of the ten boards since October 2; Kalshi has been at or below Polymarket on all of them. A new entry records the gap without a call.
Kalshi’s thirteen seat contracts now imply 58.2%, from 59.1% on October 9, so the control contract is 2.2 points over its parts after two boards under 2. The correlation implied by its four-seat joint contract rose from 0.55 to 0.71 as that contract moved from 46.5% to 49.5%. The seat-count market eased to 64.1%, 3.6 points over control, from 4.8.
Kalshi’s Ohio price fell 2 points to 59.5%, so the market takes 1.8 points off Brown’s 3.4-point poll lead. In Alaska the poll average narrowed from Peltola +2.9 to +2.35 with Kalshi unchanged at 73.5%, so the market now adds 1.7 to it. FiftyPlusOne’s control number is 72%, from 73.3%, and the models are 18 points apart.
The seat-count and Republican-state markdown entries were revised to today’s board; their leans are unchanged. No entry was closed. DDHQ’s reading is still dated October 2.
Oct 9, 2026update
Kalshi's control price fell to 60.5%, 1.3 points over its seat contracts, the first board under 2
Kalshi's control contract is at 60.5%, from 62.5% on October 8 and 63.5% on October 7, the lowest of the eight boards since October 2; Polymarket is at 62.5%. The thirteen seat contracts imply 59.1%, so control sits 1.3 points over its parts, the first board under 2 points since the entry opened. The seat-count market, summed at 51 seats and above, is at 65.3%, 4.8 points over the control contract, after 3.5 on October 8. The correlation implied by Kalshi's four-seat joint contract fell from 0.63 to 0.55 as that contract moved from 48.5% to 46.5%.
Kalshi's Alaska price fell from 75.5% to 73.5%, its October 5 level, and the market now adds 1.2 points to Peltola's poll lead of 2.9. In Iowa, FiftyPlusOne is at 52.6%, 0.6 points over DDHQ, so FiftyPlusOne is now 2 points or more above DDHQ in nine of the thirteen seats, from ten. The models are 19.3 points apart on control (DDHQ 54%, FiftyPlusOne 73.3%). Michigan's Kalshi price fell 4 points since October 7, to 67.5%, against 71% from both models.
The seat-count, model-spread and Republican-state markdown entries were revised to today's board; their leans are unchanged. No entry was opened or closed. DDHQ's page refused the daily reader with a rate-limit error for a fifth day, so its reading is still dated October 2.
Oct 8, 2026update
Nebraska's spread stayed under 10 points for a second board, and its entry is closed
Nebraska's sources are 9.5 points apart on the October 7 and 8 boards, from 10.9 on October 5: FiftyPlusOne has Osborn at 19.1%, from 17.6%, Kalshi at 27.5%, from 28.5%, and DDHQ at 18%. The entry is closed. The split it recorded remains: against a poll average of Ricketts +0.9, the market takes 3 points off Osborn and the models 5 and 4.8, against his 5.1-point miss in 2024.
Elsewhere the board moved by under 2 points. The models are 19.4 points apart on control (DDHQ 54%, FiftyPlusOne 73.4%), with Kalshi at 62.5% and Polymarket at 63.5%. Kalshi's seat-count market, summed at 51 seats and above, fell to 66% after five days of gains, 3.5 points over the control contract; the thirteen seat contracts imply 60.2%. Iowa's spread fell to 8.6 points as FiftyPlusOne moved from 55.3% to 53.1%.
DDHQ's reading is still dated October 2. The other entries were not revised and no entry was opened; North Carolina (14.9), Florida (13.9) and Georgia (10) are past 10 points but are settled seats.
Oct 7, 2026update
Kansas is 20 points apart across sources, and Kalshi's seat count runs 4.3 points over its control price
Kansas is 20 points apart, from 15 on October 5. FiftyPlusOne has Hamilton at 43%, from 38.4% on October 6, and Kalshi at 36.5%, from 34.5% on October 5; DDHQ is still at 23%. A YouGov poll fielded September 24 to October 4 (Hamilton 48, Marshall 45) is now in the Kansas table, and the poll average is Hamilton +0.5, from +0.15. DDHQ takes 5.3 points off Hamilton's polling, the market 2.7 and FiftyPlusOne 1.6.
The two models are 20 points apart on control (DDHQ 54%, FiftyPlusOne 74%), from 17.5. FiftyPlusOne is now 2 points or more above DDHQ in ten of the thirteen seats, Iowa added. DDHQ's number is still its October 2 reading: its page has refused the daily reader with a rate-limit error on October 5, 6 and 7, so whether DDHQ has published a newer one is not known. Kalshi is at 63.5% and Polymarket at 64.5%.
Kalshi's seat-count market, summed at 51 seats and above, rose for a fifth straight day to 67.8%, 4.3 points over the control contract (63.5%); the thirteen seat contracts imply 60.8%. In Alaska since October 5, Kalshi rose 3 points to 76.5% and FiftyPlusOne 3.7 to 69.4% with the poll average unchanged at Peltola +2.9, so the market now adds 1.8 points to her lead. FiftyPlusOne's markdown is under 2 points in all six Republican states the markdown entry tracks, Kansas included.
The model-spread, Republican-state markdown and seat-count entries were revised; the leans in the markdown and Nebraska entries are unchanged. Nebraska's spread fell to 9.5 points, its first board under 10 since October 3, and its entry stays open until a second board confirms. North Carolina (14.9) and Florida (13.5) are past 10 points but are settled seats. No entry was opened or closed.
Oct 5, 2026update
Nebraska's poll average turns to Ricketts +1.0, and the lean there moves to the models
Nebraska's poll average moved from Osborn +1.1 on October 2 to Ricketts +1.0. 270toWin, FiftyPlusOne and Silver Bulletin updated their averages between October 2 and 4, each now with Ricketts ahead by 0.6 to 1.6, and Decision Desk HQ's September 27 average (Osborn +3.1) left the table. Prices moved by under 2 points over the same days, so the markdowns shrank: the market now takes 2.7 points off Osborn's polling (28.5%), DDHQ 4.9 and FiftyPlusOne 5.1 (18% each). The one measured miss for Osborn, 5.1 points in 2024, now matches the models' markdown, so the October 3 lean toward the market was moved to the models. The spread is 10.9 points.
Kalshi's control contract rose 2 points to 64.5%, 1.2 under its seat-count market (65.7%); the two were 3 points apart on October 4. Its thirteen seat contracts still imply 59.3% to 60.9%, so control sits 3.6 points above its parts. The coherence entry was revised.
The model spread on control is 17.5 points (DDHQ 54%, FiftyPlusOne 71.5%). Kalshi's Maine price fell 3 points to 55.5%, and Maine is now 17 points apart between the two models. DDHQ's number is still its October 2 reading. The model-spread entry was revised; the Republican-state markdown entry is unchanged. No entry was opened or closed.
Oct 5, 2026update
Silver Bulletin read once: 72.8% on control, beside FiftyPlusOne and 19 points above DDHQ
Silver Bulletin's Deluxe forecast, read once on October 4 from its subscriber page, has Democratic control of the Senate at 72.8% with an average of 52 seats. FiftyPlusOne is at 71.6% and DDHQ at 54%, so DDHQ is the low reading of three. Kalshi (62.5%) and Polymarket (64.5%) are 7 to 10 points under the two higher models. The reading is cited in the model-spread and Republican-state markdown entries and is not a board source: the board carries only sources that can be read daily from public pages.
Silver Bulletin publishes projected margins beside its poll averages. In Ohio, Texas, Iowa and Maine its projection is within a point of its own poll average, and it has the Democrat at 74% in Ohio and Texas, the highest of any source in both. In Kansas, Nebraska and South Carolina it takes 2 to 4 points off the non-Republican's poll margin. Its Classic version, without expert ratings, has control at 70.0% and moves the six focus seats by under a point, so the ratings are worth 2.8 points of control in its model, against 18 between DDHQ and FiftyPlusOne. No lean was added: two models agreeing is not a measured result.
Seat by seat, beyond Ohio and Texas it is also the highest source in Iowa (58.9%), Kansas (41.6%) and Michigan (81.8%, about 10 points above the other three). In South Carolina (19.8%) and Florida (13.7%) it is nearer the market than DDHQ and FiftyPlusOne are. In Alaska it has Peltola at 62.9%, beside the other two models and 10 points under Kalshi's 73%. Its control number sits inside the range its own seat numbers imply.
Oct 4, 2026update
Alaska spread widens to 13 points; Kalshi's seat-count and control prices split by 3
Alaska's spread between sources widened from 7.5 points on October 2 to 13. Kalshi rose from 67.5% to 73% and FiftyPlusOne from 61.5% to 65.5%; DDHQ's 60% is still its October 2 reading. The newest poll, New York Times/Siena (September 24 to October 1), has Peltola ahead 50 to 43, and the poll average moved from 2.0 to 2.9. The gap is recorded in the existing entry on Republican-state markdowns, where the market now adds 1.1 points to Peltola's lead.
Kalshi's seat-count market, summed at 51 seats and above, rose to 65.5% while its control contract fell back to 62.5%, a 3-point gap on the first board where it exceeded 2. The thirteen seat prices imply 60%. The coherence entry now carries all three numbers.
Ohio's poll average narrowed from 4.5 to 3.3, which cut the market's implied markdown there from 2.8 to 1.2 points, under the 2-to-5-point band behind the October 3 lean on Republican-state markdowns. That lean is unchanged, since the record it rests on has not changed. The model-spread entry was revised to 18 points (DDHQ 54%, FiftyPlusOne 72%) and now names Kansas alongside Maine and Ohio. No entry was opened or closed.