The congressional result favored William Hill’s stated exposure, but individual upsets and uneven betting action made the financial picture more complicated.
Democrats won the House and Senate on Tuesday. Whether the bookmakers won money is a different question—and the answer depends less on the electoral map than on the bets sitting behind each price. The Democratic sweep avoided the congressional outcomes William Hill had identified as its greatest financial threats, while individual races created a different set of winning tickets and payment obligations.
William Hill Avoided Its Biggest Risks
William Hill entered election night with an unusual problem: its customers had created substantial exposure to outcomes its own odds considered unlikely.
“Republican success in either chamber would be a poor result for us,” spokesman Lee Phelps said before the election. Customers had backed Republican control of the House at 8/1 and the Senate at 2/1. Republican victories in both chambers would have compounded the damage. William Hill News
Neither occurred. But another risk William Hill identified did materialize: South Carolina Democrat Annie Andrews won after customers backed her at 7/4, equivalent to +175. Phelps had specifically highlighted that support as a potential payout problem. Reuters subsequently reported Andrews’ victory.
The result was favorable for William Hill’s stated congressional-control exposure and unfavorable for its Andrews liability. Without the amounts wagered across all markets, those two observations cannot be combined into a net-profit figure.
BetOnline’s Bigger Bets Told a Different Story From Its Ticket Count
BetOnline’s Election Day figures showed customers taking sharply different positions depending on whether the measure was money wagered or number of bets. In the Texas Senate race, 59% of the money backed Democrat James Talarico, while 73% of individual tickets backed Republican Ken Paxton. Senate control showed a similar split: Democrats attracted 54% of the money, but Republicans accounted for 65% of tickets. In the Texas governor’s race, Republican Greg Abbott drew both a majority of the money, at 61%, and the tickets, at 65%.
Talarico won, Democrats took the Senate, and Abbott lost. That meant the larger average wagers were on the winning side in the first two markets, while the candidate attracting most of both measures lost the governor’s race.
A bookmaker can take more money on a winning favorite and still finish ahead if the losing stakes cover the favorite’s relatively modest profit payments. Conversely, a smaller amount wagered on a longshot can create a large liability. Ticket counts alone reveal neither outcome.
Bovada and BetUS Had the Broad Result Priced Correctly
The Democratic sweep was already the favored outcome at several major election bookmakers. USA TODAY’s October 18 snapshot listed Democratic control of both chambers at -145 at Bovada and -200 at BetOnline. BetUS’s October 30 preview also offered the sweep at -200.
The prices also show why “backing the same winner” does not describe an identical financial result. A hypothetical $200 wager at -145 earns approximately $137.93 profit. At -200, the same stake earns $100. Both customers correctly select the sweep, but their returns differ by almost $38.
For the bookmaker, the reverse calculation applies: the amount owed depends on the accepted price, not simply the winner. Calling the main result correctly therefore says something about the direction of the odds, but little about the profitability of the accumulated bets. To read more about the kinds of odds and bets available at Bovada, check out our Bovada Election Odds primer here.
Prediction Markets Had a Different Business at Stake
Kalshi reported more than $2.5 billion in midterm trading volume, compared with $1.3 billion during the 2024 election cycle. (Kalshi News). Kalshi operates an exchange, so its stated revenue model is transaction fees rather than taking a financial position on which candidate wins. A payout to a successful trader is consequently not equivalent to a traditional bookmaker losing that amount from its own betting exposure.
Kalshi and Polymarket nevertheless faced a reputational test: how well their prices represented the races. South Carolina supplied a prominent upset. Reuters reported that both platforms still implied roughly a 70% chance of a Republican victory late Tuesday afternoon before Andrews won.
A 70% favorite losing doesn’t by itself disprove a probability estimate, but it does demonstrate the financial distance between identifying the more likely outcome and holding the winning contract.
