The 2028 Republican presidential nominee market trades across roughly $755M in cumulative volume on Kalshi and Polymarket, with 46 listed contenders and a live race narrowed to Vice President J.D. Vance, Secretary of State Marco Rubio, and a chase tier led by Ron DeSantis, Donald Trump Jr., and Tucker Carlson. The front-runner has been the steadiest price on the board through August 2026 while the second slot moved and the two venues split on it again. The live board above carries the current cross-platform price on every name; the market resolves at the Republican National Convention in the summer of 2028.
The 2028 Republican presidential nominee market is a multi-year position trade, not a single event, and the board reflects that structure. A field of 46 named contenders splits the probability across roughly $755M in cumulative volume, but the conviction money sits with two names: Vice President J.D. Vance carries the chalk by better than two to one over Secretary of State Marco Rubio, and everyone else trades in single digits. The two-week story into the end of August 2026 is a front-runner that has not moved and a second slot that has. Vance held flat on Kalshi while Rubio's price came off and the two venues split on him again after briefly agreeing. This page covers who the field is, what structurally moves it, and exactly how it resolves at the 2028 Republican National Convention.
J.D. Vance sits at the front of the field as the most heavily backed name, and his price has gone quiet at the top. Kalshi's Vance line traded near 32c in early June 2026, repriced into the low 40s by the middle of that month, and has sat at 44c through the back half of August. Two weeks of no movement on the most actively traded single name on this board is itself a signal: nothing in the late-summer news cycle changed how the market reads the sitting vice president. The premium is the standard one an incumbent vice president carries into an open nomination cycle, and early consolidation reinforced it. Tucker Carlson, himself a listed contender here, publicly ruled out a run of his own and named Vance as the only figure in the party capable of carrying the Trump coalition forward. The risks to that standing are the ones that move any front-runner. The administration's standing, the primary calendar, and whether a single challenger consolidates the rest of the field.
Marco Rubio is the clear second name and the price that actually moved. His Kalshi line climbed to 30c through June 2026 as his profile rose during the US strikes on Iran while Polymarket held him near 22c, and the two books closed that gap and met at 23c by the middle of August. The agreement did not last. As of August 31, 2026 Rubio trades at 19c on Kalshi and 16c on Polymarket, roughly 4c below the mid-August print with a 3c disagreement back between the venues. Both halves of that matter. The second slot is being marked down in absolute terms, and it is now the least settled price on the board, because the two deepest venues cannot agree on Rubio inside a 3c band while they agree to the cent on nearly everything trading below 5c. Note where the money sits: Polymarket carries roughly $10.4M of Rubio's $15.7M in lifetime contract volume, so the lower of the two quotes is the one with the deeper book behind it.
The chase tier has thinned rather than reordered. Ron DeSantis holds third and got there without moving, his Kalshi line parked at 5c since early June while the names around him fell, though Polymarket marks him at 2c. Donald Trump Jr. and Tucker Carlson sit next in the low single digits, Carlson at 3c on both books after halving from 6c when he ruled himself out. Donald Trump himself remains a listed contender just behind them, a third-term contract the market prices as live but remote. Nobody in that group has traded above 5c on either venue in weeks, which is the working definition of a chase tier that is not chasing. The 2028 Republican candidate field market tracks the declared-versus-undeclared layer underneath all of this.
Below the top five the board flattens into a long tail at 1c or less. Add up every priced contender and the field sums to 89c rather than 100c. Part of that is the spread the exchanges keep on 46 separate contracts, and part of it is genuine room for a nominee neither platform has listed yet. Alongside conventional names like Ted Cruz, Greg Abbott, Glenn Youngkin, Vivek Ramaswamy, and Sarah Huckabee Sanders, the exchanges have opened contracts on figures holding no political office at all, from Erika Kirk to Tom Brady and Kim Kardashian. Those listings reflect what traders asked for, not an editorial judgment about viability, and most of them price at zero. The live board above is the only honest read on which tail names are moving and which are dormant.
The 2028 Republican presidential nominee market resolves to the candidate who secures the Republican nomination for president, formally determined at the 2028 Republican National Convention in the summer of 2028. The nomination is decided by delegates accumulated through the state-by-state primary and caucus calendar and confirmed by the convention vote. The winning contender's contract pays out while every other contract resolves to zero. The listed settlement date carries to the November 2028 general election as a buffer, but the outcome is fixed the moment a candidate clinches the nomination.
The 2028 Republican nominee race runs alongside the 2028 Democratic Presidential Nominee odds, which at roughly $1.5B is the larger of the two nomination boards by volume, and both feed the 2028 US Presidential Election market and the 2028 presidential winning party odds, where the nominee boards combine into the general-election question. For everything else on the ballot, the politics prediction markets hub covers the full slate of US and international election odds.
Resolves to the candidate who wins the 2028 Republican Party nomination for President of the United States, formally determined at the 2028 Republican National Convention in the summer of 2028. The nominee is decided by delegates accumulated through the state primary and caucus calendar and confirmed by the convention vote. The winning contender’s contract pays $1 per share; all other contender contracts resolve to $0. The listed market settlement date carries to the November 2028 general election as a buffer, but the outcome is fixed when a candidate clinches the nomination. If the eventual nominee is a contender not individually listed, the market resolves per each platform’s "other" and tie rules.
The live board above ranks current cross-platform prices on all 46 listed contenders across Kalshi and Polymarket. J.D. Vance leads by better than two to one over Marco Rubio, with Ron DeSantis, Donald Trump Jr., and Tucker Carlson heading a chase tier that trades in low single digits on both venues.
The market resolves when a candidate secures the nomination, formally confirmed at the 2028 Republican National Convention in the summer of 2028. The contract carries a settlement buffer to the November 2028 general election, but the outcome is fixed the moment the nominee clinches.
Both Kalshi and Polymarket list the 2028 Republican presidential nominee market, with cross-platform pairs on most of the leading contenders and roughly $755M in combined cumulative volume. The board above compares both platforms side by side so you can see where the prices diverge.
As of the August 31, 2026 review, Vice President J.D. Vance is the favorite at 44c on Kalshi. Secretary of State Marco Rubio is second at 19c on Kalshi and 16c on Polymarket, down from a converged 23c in mid-August. Check the live board above for the current ranking.
Watch whether Marco Rubio steadies after Kalshi and Polymarket split 3c apart again at the end of August 2026, whether any challenger consolidates a chase tier in which nobody has traded above 5c, and which listed contenders follow Tucker Carlson in formally ruling out a 2028 run.