The second term of US President Donald Trump is fast approaching another milestone, with the 2026 midterms scheduled for Tuesday, November 3rd.
Trump’s Republican Party is braced for a tough set of elections this autumn, with the President’s current approval rating hovering near a record low of 37%. Historically red states like Texas are also facing unusually close elections, prompting the Republicans to schedule an unprecedented midterm convention in Dallas.
Trump’s approach continues to polarize voters, too, while driving significant trading volume on Polymarket in the midterms. Here, you can buy and sell headline outcomes like the results of governor elections in individual states, while making high-profile referendum picks.
We’ll take a closer look at the most traded markets below! We’ll also address the best value trades at the time of writing.
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Odds on Control of the Senate and the House
The November midterms will ultimately reshape the composition of the US Senate and House, right up until the next national election in November 2028. This will have a significant impact on the remainder of Donald Trump’s term in office.
The Republicans are also burdened by the weight of history, having historically lost ground and seats in both chambers. We’re unlikely to see this trend bucked in 2026, but there are different ways in which you can trade the Senate and House races!
“Democrats to Win the Senate in 2026” | “Yes” at 44¢ | 44% Chance
Currently, traders on Polymarket narrowly favor Republicans retaining control of the Senate, with this outcome carrying an implied probability of 56%. The party currently holds a 53 -47 seat majority, while continuing to benefit from a structurally advantageous electoral map.
However, trading “Yes” on the Republicans at a price of 57¢ offers minimal upside and relatively low liquidity. The implied probability of the Republicans retaining the Senate has also fallen steadily since October 26th, 2025, when it peaked at 75%.
According to the NYT, recent polls also show the Democrats building a consistent national lead of between five and six points since early June. They’re performing well in the so-called “swing” states, too, while they’ve claimed a huge 57% share of the primary votes cast so far in this electoral cycle.
Rising inflation, driven by the ongoing war in Iran, also remains a key factor ahead of the midterms. Although this cooled slightly to 3.5% in June, it remains well above the 2% target and is likely to rise further after a recent ceasefire failed.
When you consider these factors, trading “Yes” on a Democrat win in this market offers the best value. You can buy shares now at 44¢, while this price has the potential to increase further in the summer and early autumn months.
“The Balance of Power – A Democrat Sweep” | “Yes” at 44¢ | 44% Chance
Another reason to back the Democrats in the Senate race is that Polymarket’s “Balance of Power” market affords them a 44% probability of winning both chambers.
This suggests that the actual probability of them winning the Senate alone is higher than currently implied. It certainly reaffirms the idea that this particular outcome is noticeably underpriced at present.
But should you trade “Yes” on the Democrats sweeping both chambers? This is highly recommended if you’re confident that they’ll win the Senate race, as they have an 85% probability of flipping the House. They need just five seats to achieve this and retain a marked funding advantage in key swing states.
So, consider buying “Yes” shares in this market at their current price of 44¢. Although a Democratic sweep is far from guaranteed, this market also has strong upside and may create opportunities to sell for a profit.
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Referendum Issues and Individual Senate Races: Trading Other Top Markets
The midterms also allow states to propose referendums on key policy decisions. Voters can then have their say, while traders on Polymarket can speculate on how the highest-profile votes will go.
You can even trade on the outcome of individual governor and senate races, with some highly volatile and others offering excellent long-term value. Here are a couple of alternative midterm markets to keep your eye on this year.
“Billionaire One-Time Wealth Tax to Pass in California” | “Yes” at 32¢ | 32% Chance
Californians are likely to vote on a one-time wealth tax this autumn, which will be applied to billionaires in the state. This is a highly controversial piece of legislation, and trading “Yes” on it being voted in currently unlocks a probability of just 32%.
The bill certainly faces strong bipartisan opposition, with the state’s Democratic Governor Gavin Newsom aiming to defeat a proposal that he believes would significantly diminish the local authority’s tax base.
The state’s super-rich have also established the so-called “California Business Roundtable” war chest. This has currently raised over $120 million, and is being used to fund an aggressive anti-tax media campaign.
However, buying a “Yes” contract isn’t dependent on whether or not the bill actually passes. This investment can still offer value if you believe the current price of 30¢ will rise in the coming months, which is likely given the high inflation and economic anxiety that’s prevalent nationwide.
With strong grassroots support and core Democratic backing for wealth distribution measures, trading “Yes” here is a smart short-term pick. Remember, “Yes” shares have seen their price peak at 61¢ since the market opened, and this could increase again.
“Susan Collins (Republican) to Win the Maine Senate Race” | “Yes” at 34¢ | 34% Chance
The Maine Senate race has been incredibly dramatic, starting with the withdrawal of Democratic primary winner Graham Platner amid ongoing sexual assault allegations.
On the Republican side, incumbent Susan Collins is facing a significant backlash after a fatal Immigration and Customs Enforcement (ICE) shooting during a traffic stop in Biddeford. She has since clashed with Trump in attempting to manage the fallout, too, eroding different segments of her base.
Overall, this has seen Collins’ “Yes” price fall from 50¢ when the market opened to just 34¢ on July 16th. However, she remains immensely popular with voters on an individual level, while the 73-year-old is also well-funded.
What’s more, Collins retains a relatively strong moderate base in a state where Republicans have largely dominated the Senate race since the 1970s. Collins herself has won the seat five times since 1996 and remains well placed if she can ride out the current controversy.
So, buying “Yes” on Collins to win at just 34¢ offers considerable long-term value, even if she doesn’t go on to earn re-election. At the very least, her price and probability should rise as the Senate race begins to settle, creating a window of opportunity to sell in late summer or early autumn.
The Last Word – Trading the Midterms With Polymarket
While there are a number of midterm prediction markets that offer minimal value or upside, others remain underpriced and capable of delivering a profit over the next few months.
Backing the Democrats to flip the Senate offers a relevant case in point. While this remains a relatively tall order, the true probability of them achieving this aim is probably higher than the 46% currently implied.
Trading “Yes” on both the California wealth tax passing and Susan Collins being re-elected in the Maine Senate are also underpriced at present. So, buying up shares now leaves you well-placed to sell and lock in a profit in the buildup to the midterms.
Just remember to track your picks daily and follow the relevant news cycles. You can buy and sell shares anytime before your chosen market settles with Polymarket, creating much-needed flexibility as prices continue to fluctuate.
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The post 2026 Midterm Election Odds: The Best Value Prediction Markets appeared first on Casino.org.
