AFOS Weekly · USA-2026 midterms Political Risk Weekly

AFOS Analytics

Real-time political pricing
Prediction market × polls × press
no smoothed averages

Harvard Dataverse · DOI 10.7910/DVN/XRUT8U
United States·Issue №2·Week of 2026-08-06 to 2026-08-13·published thursday 07:00 BRT

What the prediction market did

The eight midterm contracts here hold USD 17.48M, up from USD 17.01M last week, and all of the week's movement sat in one chamber. Democrats to control the Senate went from 44.50% to 52.50%, crossing 50% on August 11 at 22:01 UTC. The House control book did not move at all.

Senate · Democrats

52.50%

↑ 8.00pp on the week

On USD 2.26M. It still read 45.50% on August 9. Highest of the 153 readings we hold, in a series that opens on May 16 and floors at 39.50%.

Senate · Republicans

47.50%

↓ 7.00pp on the week

On USD 1.58M. This is the lowest print of its own series, whose range is 47.50% to 58.50%. The two sides of this book now add to exactly 100.00%; last Thursday they added to 99.00%.

House · Democrats

87.50%

→ 0.00pp on the week

Deepest book of the set, USD 5.25M, and unchanged since August 11 at 20:00 UTC. Over 26 readings since July 29 it has stayed between 85.50% and 88.50%.

House · Republicans

12.50%

↓ 1.00pp on the week

On USD 4.13M. Issue No. 1 reported that this side had never moved. It moved on August 9 at 19:30 UTC, once, and stopped. In 26 readings it has taken two values: 13.50% and 12.50%.

The fifth published price, on whether the election happens on schedule, sits at 95.85%, up 0.20pp on the week, on USD 0.33M, still the smallest book of the set.

What the polls did

The disagreement comes before the average, because it is the finding. Eighteen institutes measured the same national race in the same window and came back 9 points apart. And this week the polls have a second thing to say by saying nothing: no institute published new national fieldwork in nine days. The most recent field date in the file is still August 4. The average reads D+5.95, from 22 polls.

Widest

Big Data Poll (R) · D+11

Narrowest

RMG Research · D+2

Spread between institutes

9 points

Big Data Poll surveyed 2,617 likely voters through July 29; RMG Research surveyed 2,000 registered voters through July 14. Neither is small and neither is wrong: houses assume different things about who turns out, and that assumption is most of the gap. Note where the average falls. The median institute reads D+7 and 12 of the 18 sit above D+5.95, so the mean sits below the middle institute, pulled down by a few low readings. RMG's fieldwork ends at the very edge of the 30-day window, so it leaves shortly and the average will rise on its own, without one voter changing their mind.

What the press reported

What the fixed-list outlets covered, August 7 to August 13

Six states voted on August 11, and AP News carried results from Alabama, Connecticut, Minnesota, South Carolina, Vermont and Wisconsin that day. The outlets kept returning to the Wisconsin governor's race, where Crowley beat Hong, the progressive: The Hill called it an upset on August 13, and The Guardian framed it on August 12 as Wisconsin Democrats choosing a middle path. In Minnesota, CBS News reported on August 12 that Demuth beat Lindell in the Republican primary for governor.

On August 8 the Senate passed a stopgap and took a shutdown off the table until after the election. Five outlets carried it the same day, independently: NBC News, The New York Times, The Guardian, Axios and Politico. This is the week's only high-impact event with genuinely separate sourcing, and it removes a scheduled fight from the calendar rather than adding one.

Running under both stories is a fight inside one party. On August 10 The New York Times framed the next big fight as moderates against the left, and The Washington Post wrote the same day that eleventh-hour primary upsets had muddied the race for control of Congress. By August 13 Axios described older Democrats being walloped by an anti-establishment revolt.

📌 Worth noticing: six states held primaries, a shutdown was averted, and the contract on who controls the House moved 0.00pp across the whole week. Primaries pick candidates; they do not change how many seats a party is expected to win.

Our measurement: Our file cannot speak to Wisconsin: it carries the national generic ballot only, 22 polls from 18 institutes, and no state race. What it can say is that the disagreement a miss exposes was already visible nationally, and visible before Tuesday: the institutes measuring the same national question in the same window sit 9 points apart, D+2 to D+11. A miss in one state primary is not evidence about the national number.

The crossing of the week

The comparison Issue No. 1 could not run works again this week

Two Senate contracts answer the same question by different routes: one on control of the chamber, one on how many seats Republicans win. Last week the seat-count bands added to 105.75% and the comparison was off. This week they add to 100.25%, so it runs. The bands put Republicans at 51 or more seats on 36.25% and at exactly 50 on 12.50%. The control contract prices Republicans at 47.50%, which sits 1.25pp from the tie-inclusive reading of 48.75% and 11.25pp from the majority-only one. A 50-50 chamber turns on the vice president's tie-breaking vote, and the two markets nearly agree once that seat is counted.

The chamber that moved is the one still in question

Eight points of movement in the Senate, 0.00pp in the House, across the same seven days and the same news. The House book is the deepest here at USD 5.25M and it sat still; the Senate books are smaller and they did the work. Neither moved on new polling, because there was none: the newest fieldwork in our file is nine days old.

How to read this number

The top of a series is not the top of the cycle

Democrats at 52.50% in the Senate is the highest number in the series we hold. That series opens on May 16, 2026, and it holds 153 readings. It is not the highest of the campaign, and we cannot know whether it is. The window also rolls: it covers 90 days, so yesterday it began on May 15 and next week it will begin later still. The same sentence, left unchanged, would quietly come to mean something else. That is why every superlative in this brief carries the date its series starts.

Sources

Prediction market

Polling

Press, outlets cited in sections 4 and 5

Method

Prediction market: Polymarket, read through this platform's own proxy and captured every 30 minutes, with a guaranteed daily point even when the price does not move, so the series records time and not just changes. Every price quoted here survived a capture guard: two independent readings eight minutes apart, released only if they agree within 0.20pp. The House series opened on July 29 and the Senate series on May 16, so a high here means the highest since that date, never of the cycle. Polls: a simple unweighted average over a 30-day window, currently 22 polls from 18 institutes with field dates from July 14 to August 4, no institute excluded, built from an index that says which polls exist while every number stays attributed to the institute that produced it. Poll aggregators are deliberately left out, because averaging an aggregator would mean averaging someone else's model. When an institute publishes several cuts of one round, one enters, by likely voters before registered voters before adults. No new national poll entered the file this week; the average moved only because older polls aged out of the window. Press: a fixed list of 22 outlets, chosen once and applied identically on every run, so no outlet is picked after the news breaks. This week the collection returned 66 distinct articles from 16 of them, 46 read from the outlet's own RSS and 20 through an aggregator; aggregator links are shown as headlines rather than addresses, because the address would not be the outlet's own. AFOS does not classify outlets by political leaning. Distributions: a band market reaches this page only when its bands add to between 95% and 105%, and only when they did so in every reading of the last 24 hours, so the page does not change shape between two visits on the same day. This week the Republican Senate seat market passes at 100.25% and is the only one that does. The governors market reads 104.05% now but was outside in all 8 readings of the last day; the House seat market reads 103.75% now and was outside in all 4; the turnout market reads 93.55%, and a sum *below* 100 is the opposite failure to a sum above it, meaning bands with no price rather than bands overpriced. The popular-vote margin market adds to 153.45% and is structurally incapable of closing, because one of its bands is an 'any other outcome' while the rest are cumulative; it is collected daily anyway, because it is the one contract that would allow a direct comparison with the polls if it were ever a partition. What this brief does not do: it does not forecast, it does not say which measurement is right, and it does not tell anyone how to vote.

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AFOS Analytics
Global Political Risk Intelligence · GLOBAL BY DESIGN
www.afos-analytics.com · contact@afos-analytics.com · github.com/AFOS-Analytics

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AFOS Weekly · Issue No. 2 · The Senate market changed hands this week. The House did not move, and no new poll was published. | AFOS Analytics