2028 Republican nominee odds
These are the prediction market odds for who wins the 2028 Republican presidential nomination, side by side from Kalshi and Polymarket.
J.D. Vance wins the nomination
The markets
Who will be the 2028 Republican nominee?
Kalshi · 66.4M contracts traded · Polymarket · $708.1M traded
| Outcome | Kalshi | Polymarket | Average |
|---|---|---|---|
| J.D. Vance | 44% | 51% | |
| Marco Rubio | 18% | 16% | |
| Ron DeSantis | 4.3% | 2.9% | |
| Donald J. Trump Jr. | 3.1% | – | |
| Tucker Carlson | 2.6% | 3.1% | |
| Donald J. Trump | 2.1% | – | |
| Ted Cruz | 1.8% | 1.9% | |
| Donald Trump Jr. | – | 1.8% | |
| Donald Trump | – | 1.8% | |
| Ivanka Trump | 1.2% | <1% |
What to know
- Timeline: primaries and caucuses run in the first half of 2028, and the nominee is confirmed at the Republican National Convention that summer.
- Term limits: the 22nd Amendment limits a president to two elected terms.
- Base rate: early frontrunners in open primaries often fade. Treat odds two years out as a snapshot of name recognition as much as a forecast.
How these markets resolve
- Kalshi, “2028 Republican presidential nominee”: If Thomas Massie wins and accepts the nomination for the Presidency for the Republican party in 2028, then the market resolves to Yes. Full rules
- Polymarket, “Republican Presidential Nominee 2028”: This market will resolve to “Yes” if the named individual wins and accepts the 2028 nomination of the Republican Party for U.S. president. Otherwise, this market will resolve to “No”. The resolution source for this market will be a consensus of official Republican Party sources. Full rules
How to read these odds
A price of 30¢ on a contract that pays $1 means the market puts the event at roughly 30%. Prices move with supply and demand, include fees and spreads, and can lean on long shots. When the two markets disagree by more than a few points, check whether their rules or deadlines differ. More in how prediction markets work and the favorite-longshot bias.
FAQ
Who is the favorite for the 2028 Republican nomination?
As of Sep 29, 2026, Kalshi prices it at 44% and Polymarket prices it at 51%. These are market prices, roughly the probability traders are willing to bet on, not a guarantee.
Why do Kalshi and Polymarket show different odds?
They are separate markets with different traders, fees and sometimes different rules or deadlines. A gap of a few points is normal; a large gap is worth checking against each market's rules.
How often are these odds updated?
Sikt refreshes this page from Kalshi's and Polymarket's public data several times a day. The time of the last update is shown at the top.
Are prediction market odds accurate?
Often, but not uniformly. Research on Kalshi finds prices are informative and improve as a market nears its close, but long shots tend to be overpriced (the favorite-longshot bias).
Market data from the public Kalshi and Polymarket APIs, shown for information only. Prices are midpoints or last trades and can be several hours old. Sikt Intelligence is not affiliated with Kalshi or Polymarket. Not financial or investment advice.