WTI October odds: $105 at 41% Despite a $110 Spike

WTI October odds just got a lot more interesting. On Tuesday, October 20, the expiring November WTI contract spiked to $110.48 before settling at $101.79, according to Reuters. Yet at about 06:19 UTC on October 21, Polymarket still priced "WTI hits $105 in October" at only about 40.5%. The gap comes down to one word in the rules: Active Month.

What actually happened

Oil spent Tuesday on a war-risk roller coaster. Reuters reported Brent touched $111.99, a five-month high, before settling at $108.79. The drivers were Houthi claims of strikes on Saudi energy, airport and military targets, which Saudi authorities did not immediately confirm and Reuters could not verify, plus shiptracker Kpler's count of at least 18 vessels reportedly attacked over two weeks.

Pulling the other way, Iran's president met Pakistan's army chief, a key U.S.-Iran mediator, to discuss mediation. Russian diesel cargoes are also returning to normal routes after the U.S. suspended sanctions, which we covered in our Russian diesel imports piece. The result was a huge intraday range on an expiring contract and a calmer December contract below $98.

Why $110.48 did not end the market

Polymarket's WTI markets resolve on Pyth 1-minute candles for the Active Month of ICE WTI futures. The rules say the Active Month is the nearest contract "except during that contract's final three trading sessions." At the open of the third-to-last session, the next contract takes over.

November's last trading day was October 20, so by our reading the December contract was already the Active Month during Tuesday's spike. That is the likely reason the $110 rung still traded near 16% instead of resolving Yes, and why the $105 rung is a coin flip with a lean to No. December settled at $97.82, so it needs a rally of a bit more than 7% in the remaining October sessions to hit $105.

Note also that Polymarket lists several near-identical rungs created on different dates, each counting only prices after its own creation. Always open the specific market you trade.

What Polymarket thinks

At about 06:19 UTC on October 21, the main WTI October odds looked like this on the "What price will WTI hit in October 2026?" event:

• Highs: $105 at 0.405 (0.40 / 0.41), $110 at 0.16 (0.15 / 0.17), $115 at 0.0505, $120 at 0.0205.
• Lows: $95 at 0.56 (0.54 / 0.58), $90 at 0.215 (0.21 / 0.22), $85 at 0.09.

The whole event had about $3.46M in volume, with roughly $304K in the last 24 hours. So the crowd sees December as more likely to slip under $95 than to pop above $105 before October ends. For more context on the shipping side of this, see our Hormuz traffic odds piece.

What moves the needle

A confirmed hit on Saudi export infrastructure, or more tanker attacks, could add a fast risk premium. ING analysts told Reuters the market is "pricing in a significant risk premium." A real step forward in Iran mediation would likely do the opposite. Our Iran ceasefire odds coverage tracks that thread.

Weekly U.S. inventory data is another lever. Analysts polled by Reuters expected crude stocks to have fallen by about 800,000 barrels in the week to October 16.

Put simply, WTI October odds now hinge on whether December crude can do in eight sessions what November did in one wild afternoon. With the month ending on Saturday, October 31, the last real trading session is Friday, October 30.

What to do as a reader

Read the rules before you read the chart. The headline price on a finance site is often a different contract from the one a market settles on, especially around expiry. If you trade these, check the Pyth "CLL" Active Month feed the rules point to, not the front-month quote in a news article.

Remember that oil reacts to headlines that may not be verified for hours. A 40.5% price means the crowd thinks No is somewhat more likely. Nothing here is investment advice, and war-driven markets can move further and faster than anyone expects.

Sources: Reuters via Yahoo Finance, Polymarket WTI October event and ICE WTI contract expiry calendar.