Election Day's Whole Board: $1.9 Billion Riding on Two Chambers

The board itself tells a consistent story at the top. Democrats are priced at 93 cents on Kalshi and 94 cents on Polymarket to win the House, and as polls opened this morning the price had firmed to between 94 and 95 percent (Sikt Intelligence; InvestingLive). The Senate is the live question: priced at 74 percent on Kalshi and 76 percent on Polymarket in the earliest reads, it moved through 75.9 percent on Election Day morning to 78 percent as polls opened (Vantage Predictions; InvestingLive). The Democratic sweep of both chambers is priced at 78 percent on Polymarket and 74 percent on Kalshi (KuCoin), and Kalshi's own Congress balance-of-power market has passed $106 million in volume with the sweep at 75 percent there.

The single biggest markets are the control markets themselves. Action Network's midterm guide puts the House control market above $219 million in volume and the Senate control market above $153 million. The Anti-Corruption Data Collective counts $431 million wagered on congressional markets in the 2026 cycle, nearly triple the 2024 figure (RG.org). Kalshi reported $1.33 billion in trading volume across all midterm bets as of Monday, against roughly $145 million on Polymarket's congressional markets, according to ACDC figures cited by Reuters. More than 28,000 midterm markets have been opened.

Contract counts show the same scale. Kalshi's midterm markets passed 371 million contracts traded, with Democrats at 75 percent for the Senate and 93 percent for the House on that read (PredictionMarketPicks). On Election Eve alone, Kalshi traded 286 million contracts across its Senate, House and chamber-control markets, with 195 million contracts still open. Politics dominates the cross-venue board: DeFi Rate's top-50 split shows politics taking $44 million of $51 million in 24-hour volume across 37 of the top 50 markets.

Below the control markets, the race board is deep but uneven. Kalshi lists 13 midterm toss-up races with neither candidate above 60 percent, including Iowa's Senate race, where Ashley Hinson is priced at 52 percent in the tightest big race on the board (Covers). Governor races carry real volume too: Ohio Democrat Amy Acton is priced at 82 percent and Georgia Democrat Keisha Lance Bottoms at 71 percent (Action Network), while California's governor race sits at 98 cents for Xavier Becerra on Polymarket (Action Network).

The day did not start from zero. Monday's closing aggregates, compiled by BetInt from market prices, implied a 95 percent chance of Democrats taking the House and 76 percent for the Senate (Reuters), and Kalshi's Election Eve numbers set the scale: 286 million contracts traded across its Senate, House and chamber-control markets, 28 million of them in the final 24 hours, with 195 million contracts still open and traders putting $30 million into election markets in a single day. The November catalog shows how wide the board has become: Polymarket lists 14,363 active markets for November, and its dated calendar runs to 1,610 markets, led by 1,210 election markets (Polymarket; PolymarketTrader).

The legal backdrop follows the money into Election Day. Wisconsin is the only state warning voters they could face prosecution for trading on an election they vote in, and a Competitive Enterprise Institute suit seeks to shield those voters (Deadspin). Senators Warren and Curtis have pressed both venues on election insider-trading controls, with answers due today (Financial Regulation News). And a new bill would ban candidates from betting on their own elections, with penalties of at least $10,000 (Crypto News), after several candidates were suspended this cycle for exactly that.

What the whole board says, hours before the first results: the House is close to settled in price, the Senate is a genuinely open market that has firmed toward Democrats all morning, and the sweep trades at roughly three-in-four. The $1.9 billion now has to survive contact with actual votes.