Rumpus Daily, 30 Sep 2026: Traders now expect the Fed to hold rates in October

In this episode: Traders now expect the Fed to hold rates in October; Traders cut the odds of Milei meeting Trump before September ends; Saudi pipeline restart contract collapses as oil flows resume. Two stories are driving the markets this morning. First, traders on Polymarket have swung sharply toward expecting the Federal Reserve to leave interest rates unchanged at its October meeting, even as today's inflation report could reverse that.

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 Wednesday, September thirtieth.

Sheema: Two stories are driving the markets this morning. First, traders on Polymarket have swung sharply toward expecting the Federal Reserve to leave interest rates unchanged at its October meeting, even as today's inflation report could reverse that. Second, a Polymarket contract on Javier Milei meeting Donald Trump before midnight tonight sits at sixty-three percent, despite no reporting that such a meeting is scheduled.

Neil: The Fed move is the one with real money behind it. Polymarket and Kalshi, two separate prediction markets, both put a hold at around fifty-five to fifty-six percent, and they moved in lockstep. That kind of agreement across independent books is not common.

Sheema: We'll start with the Fed, because today's inflation data lands while we're talking.

Traders now expect the Fed to hold rates in October

Sheema: Polymarket's no-change contract, which pays out if the Fed leaves its rate range untouched on October twenty-ninth, trades at fifty-six percent. A week ago it sat at forty-six. Yesterday it fell to twenty-eight before recovering twenty-eight points in a single session.

Neil: The reason for the swing is oil. Gulf crude is rerouting around the Strait of Hormuz, which is currently closed to normal traffic. Cheaper oil means lower inflation pressure, and lower inflation pressure weakens the case for tightening.

Sheema: But doesn't the December contract complicate that? Polymarket prices a quarter-point rise at the December meeting at seventy-five percent.

Neil: It's consistent. The market sees the Fed as willing to tighten but convinced that October is too soon. Hold now, hike later.

Sheema: And today's personal consumption expenditures report, the Fed's preferred measure of inflation, could undo all of it. If the PCE print comes in hotter than forecast, does the hold call survive?

Neil: Kalshi's hold contract would need to stay above forty-five percent by October second. Below that, the hike camp has its evidence. But the house call stays a hold in October and a rise in December. The fifty-six percent no-change price underrates that, on both venues.

Traders cut the odds of Milei meeting Trump before September ends

Sheema: The Milei contract now. Polymarket traders have a contract asking whether Argentina's president, Javier Milei, meets Donald Trump in person before midnight tonight, Eastern time. It trades at sixty-three percent, but it fell twenty-five points in the last twenty-four hours.

Neil: And no reporting describes such a meeting. What is actually driving the sixty-three percent?

Sheema: Milei spoke at the UN General Assembly in New York yesterday, which probably explains the earlier run to eighty-nine percent, since world leaders cross paths there. But his government says his week points toward Paris, where he meets France's Emmanuel Macron to pitch Argentina to investors.

Neil: So what is the live path to yes?

Sheema: A sideline handshake at the General Assembly that surfaces in reporting after the fact. The contract requires a consensus of credible reporting showing the two men interacting in person. With no outlet placing him in a room with Trump and the deadline tonight, sixty-three percent is too high.

Saudi pipeline restart contract collapses as oil flows resume

Neil: The Saudi East-West pipeline carries crude oil across the Arabian Peninsula to the Red Sea coast, bypassing the Strait of Hormuz. A drone strike this month took it offline, and the New York Times reported yesterday that tankers are loading oil from the line again. So why is the Polymarket contract on an official restart by tonight at four percent?

Sheema: The contract pays yes only if the Saudi government announces that the pipeline is operating. Tankers loading is not a government announcement. Saudi authorities announced the shutdown publicly, but the ministry has said nothing about a restart.

Neil: There is a second contract on a restart confirmed by October fifteenth. That one trades at forty-two percent, and it fell almost ten points on the same day the Times reported oil flowing. Why would traders push it down on good news?

Sheema: The National reports that combined traffic through the region's three main shipping chokepoints is sixty-one percent below prewar levels. The traders' case is that if Saudi crude is pivoting away from the Red Sea, the pipeline isn't fully back.

Neil: But the Times report is a direct observation of oil moving off the line. The National's reading is an inference from traffic patterns.

Sheema: Which is why the house call is that forty-two percent underrates a confirmed restart by October fifteenth. If there is no Saudi statement and no venue ruling by October ninth, and that contract falls below twenty-five percent, that is the test that proves us wrong.

Close

Sheema: Neil, thanks very much.

Neil: Thanks, Sheema.

Sheema: That's The Rumpus Daily for Wednesday, September thirtieth. We'll see you tomorrow.