Rumpus Daily, 27 Sep 2026: Traders trim ceasefire odds after Trump spurns Iran's Hormuz offer

In this episode: Traders trim ceasefire odds after Trump spurns Iran's Hormuz offer; Traders now favour Nithya Raman to be mayor of Los Angeles; Gyurov's presidential odds tumble as traders swing to Iotova. Two stories today. Traders are still pricing an Iran ceasefire at eighty-six percent through Tuesday, even after Trump rejected Tehran's offer to reopen the Strait of Hormuz.

Transcript

Opening

Sheema: Good morning and welcome to The Rumpus Daily. I'm Sheema Sharti.

Neil: And I'm Neil Matthews. Every weekday we bring you the signals from the world's prediction markets. Today is Sunday, September twenty-seventh.

Sheema: Two stories today. Traders are still pricing an Iran ceasefire at eighty-six percent through Tuesday, even after Trump rejected Tehran's offer to reopen the Strait of Hormuz. And in Los Angeles, Nithya Raman has climbed twenty points in a week to lead Karen Bass fifty-eight to forty-four on Polymarket.

Neil: The Bulgarian presidential race is worth a line too. Andrey Gyurov fell ten points to sixteen percent on Polymarket in seven days. Iliana Iotova now sits at eighty percent. That race looks settled.

Sheema: We'll get to Bulgaria in the back half. The Iran story first, because Tuesday's deadline is where the money is.

Traders trim ceasefire odds after Trump spurns Iran's Hormuz offer

Sheema: The ceasefire contract on Polymarket prices the US-Iran ceasefire holding through September thirtieth at eighty-six percent. That's after Trump turned down Iran's offer to reopen the Strait of Hormuz within a week. The price peaked at ninety-five percent on the day of the rebuff and has fallen nine points since.

Neil: What does the contract actually resolve on?

Sheema: It resolves on whether an air strike or surface-to-surface missile strike directly impacts Iran before eleven fifty-nine Iran time on Tuesday. A rejected diplomatic offer is not a strike. Traders are right to hold the price high.

Neil: Does the broader strip tell us anything about what happens after Tuesday?

Sheema: The October thirty-first contract on the same event sits at fifty percent. So traders believe the truce survives Tuesday at eighty-six percent, then assign roughly a forty-two percent chance it collapses before the end of October. The danger is after the deadline, not before it. And a president five weeks from midterm elections, with the national gasoline average near four dollars forty-eight and diesel above six forty-seven, has every reason to leave the bombing paused whatever he says publicly about Iran's terms.

Neil: Which could mean the fifty percent October contract underrates the ceasefire's survival.

Sheema: That's our read. The political calendar is doing more work than the diplomacy. Watch for any White House statement on a diesel export ban. That would tell you whether the pause is holding on the fuel side.

Traders now favour Nithya Raman to be mayor of Los Angeles

Neil: Los Angeles now. Nithya Raman is a city council member challenging Karen Bass, the incumbent mayor. Raman is at fifty-eight percent on Polymarket, up twenty points since September twentieth. What does Kalshi show?

Sheema: Kalshi, a separate venue, has her at fifty-seven percent. When two independent markets price the same candidate within a point of each other, the signal is harder to dismiss. Bass sits at forty-four on Polymarket and forty-two on Kalshi, and the gap has held near its peak since Wednesday.

Neil: Does a move that fast tend to hold?

Sheema: It can unwind just as fast. The contract resolves on December thirty-first, after the November third runoff vote, so there is plenty of runway. If both venues put Raman back below fifty percent by the end of October, the week was noise. That is what to watch.

Gyurov's presidential odds tumble as traders swing to Iotova

Sheema: Bulgaria. Andrey Gyurov, a former intelligence chief, fell to sixteen percent by Saturday. Iliana Iotova, the incumbent vice president and the frontrunner, stands at eighty percent on Polymarket. The contract resolves by October twenty-fifth.

Neil: The Friday session is the part worth understanding. Gyurov's contract ran from fourteen percent to thirty-five percent and back to sixteen, all in one day. What does a swing that wide tell you?

Sheema: It tells you a thin book. A few buyers pushed the price to thirty-five percent, found no conviction on the other side, and it collapsed back. The thirty-five percent touch was a test the bull case lost on the day. Some traders argue a runoff path: if Gyurov finishes close behind Iotova in the first round, he could absorb votes from beaten candidates. But the contract already covers any second round, and the market answered that argument by selling the price straight back down.

Neil: So what would actually prove the bull case right?

Sheema: His contract climbing back above that thirty-five percent touch once the first round is counted. Until then, Iotova's eighty percent is where this sits.

Close

Sheema: Neil, thanks very much.

Neil: Thanks, Sheema.

Sheema: That's The Rumpus Daily for Sunday, September twenty-seventh. We'll see you tomorrow.