Midterms, House & Senate Prediction Market Da
Tick-by-tick trades and L2 order-book depth for 35 Midterms, House & Senate series on Kalshi & Polymarket — midterm margin of victory, midterm voter turnout, House race winners, state ballot measures, political fundraising. 6,368 series-days covering November 2025 – present; 250.9K trades · $6.2M turnover over the last 30 captured days. Every contract captured co-located with nanosecond venue and receive timestamps — sold as day bundles, €1 per day, bought as a guest with instant download.
Midterms, House & Senate on Kalshi & Polymarket
Midterm margins and turnout, House race winners, ballot measures, fundraising.
Every series below is archived at full feed resolution — each contract file carries every trade print (price, size, side) and Level-2 order-book updates in one normalized, zstd-compressed schema. A series-day bundle holds all contracts of the series for one UTC day.
Most traded Midterms, House & Senate series (last 30 days)
Ranked by USD turnover from our own daily statistics — the series a market maker or bot builder should start with.
| # | Series | Venue | Trades (30d) | Turnover (30d) | Days | |
|---|---|---|---|---|---|---|
| 1 | House Race Winner? | Kalshi | 20,935 | $1.1M | 30 | Buy days |
| 2 | California Governor's race | Kalshi | 6,367 | $838.4K | 30 | Buy days |
| 3 | 2026 House Election Winners — Democratic party (per district) | Polymarket | 16,701 | $811.6K | 30 | Buy days |
| 4 | 2026 House Election Winners — Republican party (per district) | Polymarket | 14,227 | $811.1K | 30 | Buy days |
| 5 | Midterm margin of victory | Kalshi | 27,828 | $757.9K | 30 | Buy days |
| 6 | 2026 House Election Margins of Victory — Republican candidates | Polymarket | 64,905 | $440.4K | 30 | Buy days |
| 7 | 2026 House Election Margins of Victory — Democratic candidates | Polymarket | 63,025 | $435.2K | 30 | Buy days |
| 8 | Democratic Senate seats | Kalshi | 6,796 | $292.0K | 30 | Buy days |
| 9 | Republican house seats | Kalshi | 4,781 | $115.8K | 30 | Buy days |
| 10 | Republican senate seats | Kalshi | 3,633 | $103.4K | 30 | Buy days |
Trades and USD turnover summed over every contract of the series, from the recorded tick data; 30 days to 2026-10-12. Series without statistics in the window are omitted.
Midterms, House & Senate activity per venue
| Venue | Series | With stats | Trades (30d) | Turnover (30d) |
|---|---|---|---|---|
| Kalshi | 31 | 22 | 92,016 | $3.7M |
| Polymarket | 4 | 4 | 158,858 | $2.5M |
30 days to 2026-10-12, from our own daily statistics per contract.
Midterms, House & Senate — development since capture
462,956 trades and $24.9M of USD turnover across 32 series since 2026-07-08; busiest single series-day 2026-08-12 with $5.1M, biggest contract KXGOVFLNOMR-26-BD (2026-08-18, $4.0M).
| Month | Series active | Days | Trades | Turnover (USD) | Avg / day | Contracts traded | L2 updates | vs previous month |
|---|---|---|---|---|---|---|---|---|
| Oct 2026 (month to date) | 26 | 12 | 111,331 | $3.1M | $258.1K | 24,144 | 1.2B | — |
| Sep 2026 | 27 | 30 | 190,599 | $4.2M | $139.0K | 50,259 | 2.3B | −75.9 % |
| Aug 2026 | 32 | 31 | 150,795 | $17.3M | $557.5K | 20,368 | 897.4M | +4815.3 % |
| Jul 2026 | 4 | 24 | 10,231 | $351.6K | $14.6K | — | — | — |
Midterms, House & Senate series — trades and USD turnover summed per calendar month (UTC) over every contract, from our own daily statistics of the recorded tick data. Days = captured UTC days; a partial month shows no month-over-month change. Contracts traded and L2 (order-book) updates exist for days captured with the extended statistics.
Midterms, House & Senate — turnover by weekday
Mondays are the busiest day at about $263.0K of USD turnover, averaged over the captured days of the last 30.
| Weekday (UTC) | Avg turnover / day | USD | Avg trades | Days |
|---|---|---|---|---|
| Monday | $263.0K | 8.1K | 5 | |
| Tuesday | $202.4K | 7.3K | 4 | |
| Wednesday | $206.5K | 7.9K | 4 | |
| Thursday | $213.9K | 9.0K | 4 | |
| Friday | $253.4K | 9.2K | 4 | |
| Saturday | $156.6K | 8.4K | 4 | |
| Sunday | $148.6K | 8.6K | 5 |
Midterms, House & Senate series — average USD turnover and trades per weekday over the captured days of the last 30, from our own daily statistics; weekdays without a captured day show —.
Rising Midterms, House & Senate series — 30 days vs the 30 before
| # | Series | Venue | Turnover (30d) | Prior 30d | Growth (avg / day) | Trades (30d) |
|---|---|---|---|---|---|---|
| 1 | State legislature winners | Kalshi | $43.1K | $5.3K | +715.6 % | 1,115 |
| 2 | 2026 House Election Margins of Victory — Republican candidates | Polymarket | $440.4K | $79.2K | +456.0 % | 64,905 |
| 3 | 2026 House Election Margins of Victory — Democratic candidates | Polymarket | $435.2K | $82.4K | +428.2 % | 63,025 |
| 4 | Democratic Senate seats | Kalshi | $292.0K | $61.3K | +375.9 % | 6,796 |
| 5 | Republican senate seats | Kalshi | $103.4K | $24.5K | +321.2 % | 3,633 |
Growth of average USD turnover per captured day, the 30 days to 2026-10-12 against the 30 days before; series need ≥ 10 captured days in both windows and ≥ $10K of turnover in the current one. From our own daily statistics.
Midterms, House & Senate prediction markets — trades and turnover per day
Every captured UTC day of the last 30, summed over the 35 Midterms, House & Senate series — how much these markets trade day by day, from our own tick capture.
| UTC day | Series with stats | Contracts traded | Trades | Turnover | Buy share | L2 updates |
|---|---|---|---|---|---|---|
| 2026-10-12 | 26 | 2,261 | 11,334 | $350.4K | 50 % | 101.1M |
| 2026-10-11 | 26 | 2,632 | 14,388 | $228.2K | 61 % | 116.9M |
| 2026-10-10 | 26 | 2,576 | 13,556 | $236.0K | 57 % | 132.3M |
| 2026-10-09 | 26 | 2,163 | 10,629 | $445.3K | 57 % | 102.5M |
| 2026-10-08 | 26 | 2,130 | 9,067 | $261.5K | 62 % | 97.5M |
| 2026-10-07 | 26 | 1,733 | 8,292 | $203.5K | 60 % | 96.8M |
| 2026-10-06 | 26 | 1,763 | 7,520 | $216.7K | 66 % | 99.6M |
| 2026-10-05 | 26 | 1,906 | 8,461 | $357.6K | 71 % | 96.1M |
| 2026-10-04 | 26 | 1,812 | 7,017 | $197.2K | 54 % | 89.5M |
| 2026-10-03 | 26 | 1,498 | 5,978 | $147.1K | 63 % | 88.2M |
| 2026-10-02 | 26 | 1,688 | 6,954 | $201.6K | 64 % | 84.6M |
| 2026-10-01 | 26 | 1,982 | 8,135 | $251.7K | 64 % | 95.4M |
| 2026-09-30 | 26 | 1,937 | 7,436 | $233.1K | 69 % | 91.0M |
| 2026-09-29 | 26 | 1,422 | 4,864 | $118.5K | 59 % | 51.6M |
| 2026-09-28 | 26 | 1,535 | 4,572 | $160.8K | 40 % | 65.3M |
| 2026-09-27 | 26 | 1,811 | 5,720 | $104.4K | 62 % | 71.2M |
| 2026-09-26 | 26 | 2,176 | 7,567 | $124.5K | 61 % | 76.9M |
| 2026-09-25 | 26 | 2,592 | 10,607 | $170.6K | 55 % | 92.7M |
| 2026-09-24 | 26 | 2,841 | 11,442 | $211.3K | 51 % | 94.5M |
| 2026-09-23 | 26 | 2,159 | 10,244 | $182.0K | 47 % | 93.9M |
| 2026-09-22 | 26 | 2,229 | 11,139 | $360.2K | 64 % | 95.3M |
| 2026-09-21 | 26 | 2,333 | 11,977 | $265.6K | 60 % | 93.1M |
| 2026-09-20 | 26 | 2,483 | 12,287 | $149.4K | 43 % | 82.2M |
| 2026-09-19 | 26 | 1,633 | 6,353 | $118.6K | 59 % | 78.7M |
| 2026-09-18 | 26 | 2,998 | 8,768 | $196.3K | 69 % | 77.8M |
| 2026-09-17 | 26 | 2,194 | 7,441 | $131.1K | 58 % | 90.8M |
| 2026-09-16 | 26 | 1,547 | 5,584 | $207.6K | 52 % | 84.7M |
| 2026-09-15 | 26 | 1,498 | 5,651 | $114.2K | 69 % | 73.5M |
| 2026-09-14 | 26 | 1,262 | 4,348 | $180.7K | 68 % | 81.2M |
| 2026-09-13 | 26 | 1,118 | 3,543 | $63.8K | 66 % | 75.4M |
Per UTC day, summed over every Midterms, House & Senate series that has statistics for that day, from every trade print of every contract in our tick archive. Trades and USD turnover are exact; contracts traded, buy share and L2 (order-book) updates exist for days captured with the extended statistics — earlier days show —.
Most traded Midterms, House & Senate contracts on 2026-10-12
The single event contracts with the most USD turnover on the newest captured day — with open and close price and the outcome implied by the last print.
Single contracts ranked by USD turnover on 2026-10-12 (UTC), from every trade print in our tick archive. Prices quote 0..1; the implied outcome reads the last print of the day (≥ 0.97 Yes/Up, ≤ 0.03 No/Down) — venues publish the official result. Each contract’s day file is sold individually, the whole series day as a bundle.
Kalshi Midterms, House & Senate series
Largest archive first. Each series page lists its exact coverage, day count and recent days; day bundles are bought in the shop calendar.
Polymarket Midterms, House & Senate series
Largest archive first. Each series page lists its exact coverage, day count and recent days; day bundles are bought in the shop calendar.
| Series | Venue | Interval | Days | Coverage | Size | Price/day | |
|---|---|---|---|---|---|---|---|
| 2026 House Election Winners — Republican party (per district) | Polymarket | annual | 322 | November 2025 – present | 49.8 GB | €1 | Buy days |
| 2026 House Election Winners — Democratic party (per district) | Polymarket | annual | 322 | November 2025 – present | 49.3 GB | €1 | Buy days |
| 2026 House Election Margins of Victory — Republican candidates | Polymarket | annual | 70 | August 2026 – present | 42.6 GB | €1 | Buy days |
| 2026 House Election Margins of Victory — Democratic candidates | Polymarket | annual | 70 | August 2026 – present | 38.3 GB | €1 | Buy days |
Why buy Midterms, House & Senate prediction-market data here
Four things every page on this site is built on — and the reason the numbers above exist at all.
We record everything
The complete public feed of each venue as it was published: every Level-2 snapshot and update at the venue's full book depth, every trade with its aggressor side, every quote, funding, mark-price and liquidation event — for every instrument the venue lists, every UTC day since we added the venue. Nothing sampled, no top-N cut, no on-demand capture.
Institutional grade
Captured co-located at the venue with the exchange timestamp and our receive timestamp in integer nanoseconds, an event-id chain that makes any gap visible, and one normalized schema across 35+ venues — the same capture our own high-frequency trading engine and enterprise feeds run on.
€1 per instrument-day
Any instrument-day is €1, series-day bundles start at €1 — no subscription, no minimum order, no tiers to unlock. Credit packs lower the effective price and never expire, and every venue has free full-day samples to test against first.
Self-service for everyone
Pick the days in the Data Shop, pay by card as a guest and download immediately — no sales call, no enterprise contract, no KYC. Coding agents buy the same files through the MCP server, and the free Agent Skill teaches them the format.
Agents: /llms.txt · MCP server /mcp · every page as markdown via Accept: text/markdown
Midterms, House & Senate prediction-market data — FAQ
Does Kalshi have House race markets?
Yes — House Race Winner (KXHOUSERACE) markets per district, midterm margin-of-victory and voter-turnout series, state ballot measures, political fundraising and NYC statistics.
How is election prediction-market data sold?
One purchase covers every contract of the series for one UTC day — every trade print and the complete Level-2 book per contract, captured co-located with nanosecond timestamps — €1 per series-day, bought as a guest with instant download.
How far back does the Midterms, House & Senate data go?
Coverage runs November 2025 – present — 6,368 series-days across 35 series on Kalshi & Polymarket. Each series page lists its exact span.
Can I get Midterms, House & Senate prediction-market data as CSV or Parquet?
Yes — trades export as gzipped CSV or Parquet at no extra cost, with integer microsecond UTC timestamps that load straight into pandas, polars or DuckDB. Both venues record full order-book depth without a separate BBO stream, so book data ships in the native tick file — the free reader script converts it locally. See the formats overview.
How much does Midterms, House & Senate prediction-market data cost?
€1 per series-day bundle — every contract of the series for that UTC day — no subscription, no minimum order. Pick days in the shop calendar, pay as a guest, download immediately.
Do I need an account or a sales call?
No. Pick the Midterms, House & Senate series-days in the Data Shop, pay by card as a guest and download immediately — no subscription, no minimum order, no KYC, no enterprise contract, no sales call. Coding agents buy the same bundles through the MCP server.
How is the Midterms, House & Senate data captured?
Co-located at the venue, message by message: every Level-2 update and every trade print carries the exchange timestamp and our receive timestamp in integer nanoseconds, an event-id chain makes any gap visible, and one normalized schema across 35+ venues means a parser written for Binance reads these files unchanged. It is the same capture our own high-frequency trading engine runs on — nothing sampled, no top-N cut.
What was the busiest Midterms, House & Senate trading day?
2026-08-12 — $5.1M of USD turnover over 35,697 trades in a single series-day. Since our statistics began on 2026-07-08, 32 Midterms, House & Senate series recorded 462,956 trades and $24.9M in total; the biggest single contract was KXGOVFLNOMR-26-BD on 2026-08-18 at $4.0M. Mondays are the busiest weekday at about $263.0K per day.