ACDC: $431 Million Bet on Congressional Prediction Markets, and 96% Can Be Moved for $3,500 or Less

The Anti-Corruption Data Collective (ACDC) said on 2 November 2026 that $431 million had been wagered on this year's congressional races across Kalshi, Polymarket and Polymarket US, and that 96% of live order books can be moved five cents for $3,500 or less, one day before US Election Day.

The figures come from ACDC's updated Gambling on Democracy dashboard and its fourth briefing, which covers prediction markets on all 435 House seats and 35 Senate seats that voters decide on 3 November 2026. The data is current to 29 October.

How big the congressional prediction markets have become

ACDC's count of $431 million is nearly triple the 2024 cycle. The group revised its 2024 total from $92 million to about $124 million after finding markets it had missed; its dashboard shows $123.8 million. Kalshi accounts for more than $286 million, nearly twice Polymarket and Polymarket US combined.

The $431 million covers congressional races only and excludes governor, mayor and state contests. Kalshi separately says more than $1.2 billion has been traded across all its midterm markets, including governors, according to Fox News, so the two numbers measure different things.

ACDC says its earlier forecast of $1.1 billion to $1.4 billion in congressional wagers now looks unlikely to be reached.

Volume is concentrated. The Texas Senate race is the most-bet market, with volume that "neared $64M" in the briefing and $66.9 million on the dashboard. The briefing says the top five states hold 59% of volume, while the dashboard says five races hold 78% of the volume in the top 15 races. For the state's separate gambling stakes in the same election, see Gamingo's Texas election report on casinos and sports betting.

What $3,500 buys in a thin market

ACDC found that 96% of 15,985 live congressional order books can be moved five cents for $3,500 or less. That sum is the maximum personal campaign contribution. The first version of this finding came on 9 September, when ACDC reported that 97% of 11,011 live markets on 1 September could be moved the same amount for $3,500. CNBC ran that analysis the same day.

The measure is the notional cost of shifting the displayed price by five cents. It is not the cost of changing an election result. In September, ACDC said an order of about $1 could move 64% of Polymarket markets without finding a counterparty.

The order books are from 28 October. The share of markets movable for under $1 fell 29% from the first briefing, when it was 57%, but spending less than $100 still moves 66% of markets. In 90% of the 470 races, the most expensive market costs under $25,000 to move.

Kalshi's flagging tool and the integrity findings

Briefing 4 analyzes Kalshi's new flagging system, which uses a $10,000 volume cut-off. ACDC concludes that the platform's new transparency tools fall short of giving meaningful new data on price manipulation, foreign interference and wash trading. That is ACDC's assessment of the tool.

The briefing adds several findings on trading behavior:

• $25.5 million has been wagered on "knowable" markets, where people inside campaigns could know the answer.
• ACDC flagged 591 suspicious round trips by 544 Polymarket wallets in 22 markets. They moved $618,395 for $34 in total profit.
• 79% of Polymarket congressional trades involve highly capitalized or algorithmic accounts.
• The top 1% of wallets held 75% of Polymarket volume in October, against 79% in 2024.

Wallet behavior on Polymarket is also under scrutiny elsewhere. Gamingo has reported on Polymarket's probe of fresh wallets that traded the Israel election and on trading resuming after a third-party breach.

Policy asks and the jurisdiction fight

ACDC wants platforms to drop markets on outsider candidates and on "knowable" questions, and wants campaigns to bar staff from trading. It also says lawmakers should ban election markets and back legislation giving jurisdiction to the states.

The jurisdiction point rests on the Commodity Futures Trading Commission (CFTC), the federal regulator of onshore prediction markets. ACDC says the CFTC is "preventing the states from applying their own rules". The briefing also notes that Portugal banned Polymarket in January.

Michelle Kendler-Kretsch, an ACDC research fellow, said in the group's 9 September release that the conditions for market accuracy are not being met. Election-linked wagering has drawn regulator attention before; see Gamingo's earlier coverage of the UK Gambling Commission's probe into election date bets.

What operators should watch

For operators, payment processors and compliance teams, the report points to the thin-liquidity problem rather than headline volume. With 90% of congressional markets under $10,000 in volume, price signals on many contracts are cheap to distort, which is the basis of ACDC's call for market removals and staff trading bans. Whether any of those steps happens, or whether Congress or the states act after the midterms, is not addressed in the briefing.

Status reviewed on 2 November 2026. Figures come from ACDC's dashboard and Briefing 4, with data current to 29 October and order books from 28 October. More regulation news and North America coverage.