Justin Murphy pulled off a late upset in the New Jersey Republican Senate primary, something prediction markets did not see coming.
Heading into Tuesday’s primary, Murphy was a distant third trading around 2% on both Polymarket and Kalshi to win the GOP nomination to face off against incumbent Democratic Sen. Cory Booker. Former TV newsman Alex Zdan had trended above 80% to win the nomination, even late into election day.
Oddly, the outcome likely doesn’t matter heading to November, where Booker is largely seen by markets, media, and polls as a safe reelection since a Republican has not won a New Jersey seat since 1972.
Still, for this all-but-meaningless primary, Polymarket ultimately saw more than $460K in trading volume, and Kalshi more than $150K.
Prediction markets miss New Jersey governor race
The interesting part is not just that Murphy won, but that he did it from behind the market’s top tier. Despite the large gap on the markets, Murphy emerged with the nomination, carrying 33.3% of the vote. Zdan came in third with 26.9% of votes behind Richard Tabor’s 29.2%.
Traders clearly found the contest worth watching, but the market still did not fully capture voter sentiments in the Garden State. Somehow, Murphy pulled off the win with negative dollars in his campaign war chest, according to the Federal Elections Commission.
In a four-way race with no clear frontrunner and almost zero polling or attention from the media or national GOP donors, that kind of miss is easier to make than it looks after the fact.
Fractured New Jersey GOP governor field
Murphy’s win fits the broader shape of the race. Poorly differentiated candidates split the Republican field. And none of them had a realistic path to beating Booker in November.
That meant the primary was never really about who would become a credible general-election threat. That might help explain why a TV reporter’s recognition could help boost a market’s confidence.
Multiple national media outlets framed Murphy’s win as the result of a weird and competitive intra-party race, not a sign of any real November movement. That lines up with the market story, too.
The trading interest was real, but the broader political consequences were limited because Booker remained heavily favored regardless of which Republican emerged.
Why the volume mattered
The volume stands out because the race itself did not. More than $600,000 combined on the two major prediction markets is a significant total for a contest that barely moves the November 2026 midterm elections board.
It shows traders were interested in the nomination fight as a small but tradable event, even if they understood that the winner was almost certainly headed for a difficult fall campaign.
It also shows how prediction markets can still draw action on races with little general election relevance when the primary field is messy enough. The New Jersey contest had enough uncertainty, enough interesting candidates, and enough late attention to keep money flowing, even though the eventual winner was always going to be a heavy underdog against Booker.
Rough Tuesday for prediction markets
New Jersey delivered a miss for prediction markets in a race that barely mattered. Still, trading volume was strong enough to show that prediction markets will engage with low-consequence political contests when the field is chaotic.
It was also the second major miss for prediction markets this week, as they also whiffed on the Iowa GOP governor primary.
Murphy was not the market favorite for the New Jersey GOP Senate nomination, yet he won, and traders still found the race worth more than half a million dollars across platforms.
It was useful as a test of how prediction markets handle a fractured, low-visibility race with a late-breaking winner. In this case, the answer was: well enough to attract money, not well enough to get the final result right.
