Short Answer

A final nuclear deal between the US and Iran by December 31 is not expected. Negotiations initiated by the June 2026 Memorandum of Understanding have unraveled amid resumed hostilities, economic sanctions, and a lack of active diplomatic engagement, with the market pricing this outcome at 11.0%.

1. Market Behavior & Drivers

The market's perceived probability of a final US-Iran nuclear deal by mid-2026 has declined following the collapse of an interim agreement. The drop in implied odds from 15.5% on August 18 to 10.5% on September 1 coincides with reports that a June 2026 Memorandum of Understanding has unraveled. The low on September 1 aligns with a statement from Iran's president urging the US to return to the failing interim deal, which signaled a breakdown in the diplomatic process.
This price movement occurred on zero traded volume. The decline therefore reflects adjustments based on public information rather than price discovery from active market participants.
  • Since last update (~28d): New longer-term outcomes increased market probability +6.5pp to 11.0%, widening the edge.
  • August 13, August 18, and August 31 outcomes resolved "no", clearing near-term uncertainty.
  • September 30 market probability compressed -13.2pp to 0.8% and was market_led.
  • Our confidence score increased +1.0pp, now standing at 8.0.
  • A final nuclear deal appears highly unlikely given irreconcilable preconditions.
  • The June 2026 Memorandum of Understanding unraveled amidst resumed hostilities and stalled negotiations.
  • New U.S. secondary sanctions, including 'Operation Economic Outcast,' create a costly stalemate.

Who Wins and Why

Outcome Market Model Why
October 31 2.5% 1.2% The June 2026 Memorandum of Understanding has unraveled, leading to resumed hostilities and sanctions.
November 30 6.0% 3.0% The June 2026 Memorandum of Understanding has unraveled, leading to resumed hostilities and sanctions.
December 31 11.0% 5.5% The June 2026 Memorandum of Understanding has unraveled, leading to resumed hostilities and sanctions.

Current Context

As of September 1, 2026, no final US-Iran nuclear or peace deal is in place [1][2]. An interim Memorandum of Understanding (MoU), signed in June 2026, has unraveled [1][3][4][5]. This MoU aimed for an immediate ceasefire and 60 days of negotiations [1][6][5][7]. However, the 60-day deadline expired in mid-August 2026, and diplomatic efforts subsequently collapsed [2]. President Trump declared the MoU "over" in July 2026 [2].
Hostilities resumed, US maintains pressure, Iran seeks reciprocity. Tensions are high following a resumption of direct hostilities between the two nations [1][3][8][7]. The U.S. conducted strikes on Larak Island, prompting Iranian attacks on U.S. bases in Jordan [1][3][8][7]. The Trump administration has threatened further retaliation [1][8]. The U.S. continues a maximum-pressure campaign, implementing naval blockades and new secondary sanctions against Iranian banks, which began in July 2026 [1][8][7][9][2]. This includes renewed conflict over the status of the Strait of Hormuz [2]. Iranian officials report significant strain on their economy [1][8][7][9]. Iranian President Masoud Pezeshkian stated on September 1, 2026, that Iran is willing to "immediately reciprocate" if the U.S. returns to the commitments outlined in the June MoU [1][6][5][7].
Iran's nuclear program status unclear after previous strikes. While the June 2026 MoU contained language stating Iran would not develop nuclear weapons, the overall status of Iran's nuclear program remains unclear [10][2]. This follows extensive U.S. and Israeli airstrikes on Iranian nuclear facilities earlier in 2026 [10][2].
Sources (10)
  1. 1Iran President Urges The U.S. To Return To Earlier Interim Peace Dealforbes.com
  2. 2Iran: U.S. Economic Sanctions and the Authority to Lift Restrictionscongress.gov
  3. 3Iran urges US to comply with interim deal after Trump threatens further strikes | Quews Newsquews.news
  4. 4Iran President Says Tehran Would ‘Immediately’ Reciprocate if US Returns to June Dealenglish.aawsat.com
  5. 5Iran's president says his country would return to ceasefire agreement if US does | AP Newsapnews.com
  6. 6Iran will reciprocate if US returns to Islamabad commitments, Pezeshkian says | Iran Internationaliranintl.com
  7. 7Iran signals reciprocity hinging on US return to June MoU, seeks alternate economic pathways | Rudawrudaw.net
  8. 8Iran is again talking peace after Trump's warning of retaliation, consequences | Live Updates from Fox News Digitalfoxnews.com
  9. 9WRAPUP 1-Iran urges US to comply with interim deal after Trump threatens further strikes | Internationaldevdiscourse.com
  10. 10Iran and Nuclear Weapons Productioncongress.gov

2. Price Chart

Historical Price (Probability)

Outcome probability
Date

3. Market Data

Contract Snapshot

This market resolves to "Yes" if, by the specified date (11:59 PM ET), the United States and Iran have mutually signed or formally adopted a qualifying written diplomatic instrument. This instrument must be identified as the final deal from their June 14, 2026, memorandum of understanding and establish concrete, measurable obligations limiting Iran's nuclear program. If no such qualifying instrument is signed or adopted by the deadline, the market resolves to "No."

The "specified date" varies by contract, with examples including September 30, October 31, November 30, and December 31. A special condition allows the market to remain open for up to 28 days after the specified date if the full text of a potentially qualifying instrument is not released, with resolution then relying on official announcements and credible reporting.

Available Contracts

Market options and current pricing

Outcome bucket Yes (price) No (price) Last trade probability
October 31 $0.03 $0.98 3%
November 30 $0.06 $0.95 6%
December 31 $0.11 $0.90 11%

Market Discussion

Market participants are largely pessimistic about a final US-Iran nuclear deal being reached by the specified dates. Key arguments for "No" center on stalled negotiations, ongoing disputes over inspection commitments, and heightened tensions since an interim pact expired without a final accord. While Iran's president has signaled conditional readiness, the market's low "Yes" probabilities (1-11% across various deadlines) reflect a strong consensus that diplomatic hurdles are unlikely to be overcome soon.

4. Trust Index

Octagon Trust Index Polymarket 68 Caution

Largest single print on us-iran-final-nuclear-deal-by-august-13-2026-20,260,621,201,255,150 carried 64% of its 32,132-contract tape (contract holds 7.4% of the event's money; print is 51d old)

Integrity risk· Large trades

How it adds up
Integrity80% of score69Caution
Trade quality20% of score63Caution

Includes the cost to trade: a $10,000 order loses about 15% of the price to slippage.

Trust score68Caution

Weighted blend with hard caps — a critically weak safety pillar, or a severe trading anomaly, caps the total regardless of the rest. Full methodology · About the Trust Index

Trust profile
Integrity5 screens run · 4 don't apply · 1 awaiting data

5. What catalysts could compel the Trump administration and Iran to restart formal nuclear deal negotiations before the end of 2026?

MOU DateJune 14, 2026 [1][2][3]
MOU Negotiation Periodextendable 60-day period [1][2][3]
Deal Confidence by Dec 31, 2026Low [1][2][3]
U.S. and Iran initiated nuclear deal negotiations but face low confidence. On June 14, 2026, the U.S. and Iran entered a memorandum of understanding, establishing an extendable 60-day period for negotiating a final nuclear deal. This deal focuses specifically on enriched material stockpiles and enrichment limits [1][2][3]. However, prediction markets indicate low confidence in completing a final deal by December 31, 2026, primarily citing unrealistic timelines and significant technical gaps [1][2][3].
Overcoming stalemate requires addressing existing issues and direct leadership. For progress in negotiations to occur, catalysts that move beyond the current impasse are essential. These include concrete resolutions on existing high-enrichment stockpiles or the publication of definitive settlement criteria [1][4][2]. Major policy differences, such as U.S. zero-enrichment demands versus Iranian interest in the status quo, remain significant hurdles [1][4][2]. Furthermore, a direct initiative from President Trump could compel a restart of formal negotiations, echoing a past scenario where new Iran talks were announced after a planned attack was called off [5].
Sources (5)
  1. 1What does the US-Iran agreement reveal about the true...arabnews.jp
  2. 2US-Iran Final Nuclear Deal by… Odds & Prediction Market Analysis | CryptoSlatecryptoslate.com
  3. 3US-Iran Final Nuclear Deal by…? Predictions & Odds 2026 | Polymarketpolymarket.com
  4. 4Iran Update, February 26, 2026understandingwar.org
  5. 5Iran Says Hormuz Talks Underway, Stocks Rise as Oil Plunge | Bloomberg Daybreak: US Editionyoutube.com

6. What is the latest intelligence on Iran's nuclear program capabilities following the 2026 U.S. and Israeli airstrikes?

Airstrikes CommencementFebruary 28, 2026 [1]
Nuclear Program DamageTotal destruction lacking; Iran continues "nuclear hedging" [1][2][3][4]
Nuclear Deal Probability (late 2026)Below 15-20% [5][6][7][8][9]
US-Israeli airstrikes aimed to dismantle Iran's nuclear capabilities, with contested success. The United States and Israel initiated large-scale airstrikes against Iran on February 28, 2026, with the stated objective of dismantling Iran's nuclear and ballistic missile capabilities, leading to escalating conflict throughout the year [1][10][11]. Despite the stated intention to obliterate facilities, the full extent of the damage inflicted remains contested by intelligence reports [1][2][3][4]. Concurrently, Iran's nuclear program has been referenced as having been "dealt with" in the context of an agreement to reopen the Strait of Hormuz [12].
Partial damage is evident, but Iran continues nuclear hedging, with low deal prospects. While reports indicate some Iranian facilities sustained damage, comprehensive evidence of their complete destruction is not available, and Iran has continued its strategy of "nuclear hedging" [1][2][3][4]. Prediction markets reflect the ongoing hostilities and the breakdown of negotiations for a June 14, 2026, memorandum of understanding. Consequently, the probability for a near-term US-Iran Final Nuclear Deal by late 2026 generally stays below 15-20% across various platforms [5][6][7][8][9].
Sources (12)
  1. 1Iran in 2026: Six months after the US/Israeli strikescommonslibrary.parliament.uk
  2. 22026 Iran war | Deal, Explained, United States, Israel, Strait...britannica.com
  3. 3What Are Iran's Nuclear and Missile Capabilities?cfr.org
  4. 42026 Iran waren.wikipedia.org
  5. 5US-Iran Final Nuclear Deal by…? Predictions & Odds 2026 | Polymarketpolymarket.com
  6. 6US-Iran nuclear deal? Odds & Predictions 2026kalshi.com
  7. 7US-Iran Final Nuclear Deal by…? — Prediction Markets | FRCresearchfrc.com
  8. 8US-Iran Final Nuclear Deal by…: When Will It Happen? December 31 Leads at 30% | Live Oddspredictioncircle.com
  9. 9US-Iran Final Nuclear Deal by which date? - Compare Odds on 3 Platforms | CoinRithmcoinrithm.com
  10. 10Iran Update: US and Israeli Strikes, Feb. 28, 2026understandingwar.org
  11. 11Israel/US-Iran conflict 2026: Background and UK responsecommonslibrary.parliament.uk
  12. 12Iran Says Hormuz Talks Underway, Stocks Rise as Oil Plunge | Bloomberg Daybreak: US Editionyoutube.com

7. How do the stated preconditions for a new nuclear deal from the Trump administration and the Pezeshkian government compare?

MOU Signing DateJune 17, 2026, with a 60-day negotiation window [1][2][3]
Trump's Inspection DemandIAEA access to nuclear sites bombed during the conflict [3]
Iran's Stance on InspectionsPushed back against inspection requirements [3][4]
Negotiations for a new nuclear deal between the Trump administration and the Pezeshkian government have stalled. An initial memorandum of understanding (MOU) signed on June 17, 2026, set a 60-day window for a final deal, but talks remain at an impasse [1][2][3]. The primary point of contention centers on inspection requirements, which have led to the current standstill in discussions [3][4].
President Trump demands verified inspections, shows no urgency for a deal. His administration has stated clear preconditions, specifically requiring verified inspections by the IAEA at nuclear sites that were bombed during the conflict [3]. As of September 1, 2026, Trump has threatened to abandon talks without these verified inspections and has reportedly indicated he is in no hurry to reach an agreement [3][5].
Iran resists specific site inspections, previously sought broader concessions. The Pezeshkian government has actively pushed back against these specific inspection requirements for IAEA access to bombed nuclear sites [3][4]. Earlier in 2026, Iran's broader preconditions for peace included recognition of its nuclear rights, payment of reparations, and international guarantees, which analysts largely considered non-starters for the U.S. and Israel [6][2].
Sources (6)
  1. 1Policy Alert: Urgent Questions for Congress on the Iran MOUfddaction.org
  2. 22025–2026 Iran–United States negotiationsen.wikipedia.org
  3. 3Inspection dispute cools US-Iran deal odds to 22.5% on Polymarket - Blockchain.Newsblockchain.news
  4. 4What the Trump-Iran agreement says about Lebanon...aljazeera.com
  5. 5US-Iran Peace Prospects Dim as Trump Rejects Truce Extension | Bloomberg Businessweekyoutube.com
  6. 6What to know about feasibility of Iran's 3 preconditions for...english.news.cn

8. Which new secondary sanctions has the U.S. imposed on Iran since July 2026, and what has been their reported economic impact?

Rial DevaluationOver 2 million rials to the dollar [1]
Inflation RateNear 90% [1][2]
Nuclear Deal ProbabilityBelow 15-35% before 2027 [3][4][5]
The United States has imposed new secondary sanctions on Iran since July 2026, notably launching 'Operation Economic Outcast' in August 2026. This initiative expanded secondary sanctions risk across five critical Iranian economic sectors: digital assets, technology, gold, aviation, and shipping [6][7][8]. Treasury Secretary Scott Bessent also announced the U.S. intention to impose new secondary sanctions on a weekly basis, specifically targeting financial institutions that facilitate Iranian transactions [6][9][7].
The new sanctions have severely impacted Iran's economy and currency. The reported economic consequences include a severe devaluation of the Iranian rial, reaching over 2 million rials per U.S. dollar [1]. This currency depreciation has coincided with heightened inflation, reported at nearly 90%, and increased domestic scarcity of essential goods [1]. These economic pressures have been further exacerbated by an ongoing U.S. naval blockade [1][2].
Confidence in a U.S.-Iran nuclear deal remains low. As of September 1, 2026, prediction markets indicate a pessimistic outlook for a final U.S.-Iran nuclear deal occurring. Probabilities for such a deal being reached before 2027 generally remain below 15-35%, with variations depending on the specific platform and deadline being assessed [3][4][5].
Sources (9)
  1. 1U.S. unveils new economic sanctions to isolate Irannpr.org
  2. 2Iran says it is 'fully prepared' to counter widened US...bbc.com
  3. 3https://polymarket.com/event/us-iran-final-nuclear-deal-by-20260621201254412/us-iran-final-nuclear-deal-by-july-31-2026-20260621201255151polymarket.com
  4. 4US-Iran Final Nuclear Deal by September 30, 2026? — Polymarket Odds & Price | PredEdgeprededge.com
  5. 5US-Iran nuclear deal? Odds & Predictions 2026kalshi.com
  6. 6Treasury Launches Unprecedented Campaign Against...home.treasury.gov
  7. 7US threatens countries doing business with Iran, but holds...reuters.com
  8. 8Trump's latest wave of Iran sanctions: Which 60 entities are...aljazeera.com
  9. 9Bessent expects new US secondary sanctions weekly...jpost.com

9. What role might domestic political pressures in the U.S. and Iran play in altering their leadership's negotiation stances in late 2026?

Negotiation StatusOn hold as of late 2026, no talks scheduled [1][2]
U.S. Naval BlockadeRemains in effect [1][2]
Iranian StanceCurrently no negotiations with the US [3]
US-Iran negotiations remain suspended following a critical deadline. As of late 2026, negotiations between the U.S. and Iran are on hold, with no talks currently scheduled [1][2]. This diplomatic halt follows the expiration of a 60-day deadline set by a June 2026 Memorandum of Understanding [1][2]. In late August 2026, President Trump confirmed the absence of scheduled discussions, a stance echoed by an Iranian foreign ministry spokesman who affirmed that Iran presently holds no negotiations with the United States [1][3].
An ongoing naval blockade contributes to a significant global impasse. The United States' naval blockade against Iran remains in effect, creating an impasse that significantly impacts global affairs [1][2][4]. This situation unfolds approximately six months after the United States and Israel initiated a war with Iran [5].
Research does not detail domestic political pressure's influence. The provided research information does not detail the specific role of domestic political pressures within the U.S. or Iran in influencing their leadership's negotiation stances in late 2026 [1][2][4][5][3]. While the facts outline the current state of negotiations and the reasons for the present impasse, they do not directly link these developments to internal political dynamics or pressures in either nation.
Sources (5)
  1. 1Iran war is far from over as deadline for a deal passesapnews.com
  2. 2Trump announces "crushing economic operation" on Iran...cbsnews.com
  3. 3Iran Says Hormuz Talks Underway, Stocks Rise as Oil Plunge | Bloomberg Daybreak: US Editionyoutube.com
  4. 4Trump Reverts to Economic Squeeze of Iran; Colombia Quake Toll Tops 260 | Bloomberg Daybreak: US...youtube.com
  5. 5Warsh At Jackson Hole; Iran Says Diplomacy Not Impossible | Bloomberg Daybreak: US Editionyoutube.com

10. What Could Change the Odds

Key Catalysts

As of September 1, 2026, no active final U.S.-Iran nuclear deal exists; instead, the countries are engaged in a conflict that began on February 28, 2026, and remains in a costly stalemate [1][2][3][4][5]. Diplomatic efforts center on a previously signed, but now unraveled, June 2026 Memorandum of Understanding (MOU) intended to halt the conflict and secure the Strait of Hormuz [1][3][4][5][6]. Iranian President Masoud Pezeshkian has stated Iran will immediately reciprocate if the U.S. returns to the terms of this June MOU [1][3][4][5][6]. Prediction markets remain skeptical of a final nuclear deal in the near term, with probability odds for a deal before 2027 generally remaining below 50% as of late summer 2026 [7][8].
The geopolitical landscape is characterized by continued U.S. airstrikes, such as on Larak Island, and retaliatory Iranian actions, including strikes on bases in Jordan, alongside economic pressure via the 'Economic Outcast' sanctions campaign, and the continued obstruction of the Strait of Hormuz [9][10][11]. In June 2026, President Trump announced that a deal with Iran was complete, which initiated a 60-day period of negotiations regarding Iran's nuclear program and U.S. sanctions, though no mutually agreed upon text was released [12]. A June 2026 memorandum of understanding states Iran reaffirms it shall not procure or develop nuclear weapons; however, Iranian and U.S. accounts of the broader agreement's contents have differed significantly [12][13]. An April 8, 2026, ceasefire between the U.S. and Iran has been described as being on life support due to intermittent fighting, a retaliatory U.S. blockade of Iranian shipping, and Iran's de facto closure of the Strait of Hormuz [12][14]. The Iran Nuclear Agreement Review Act (INARA, P.L. 114-17) governs congressional oversight for any agreement related to Iran's nuclear program, providing a framework that the Administration may seek to navigate or bypass [12][14][15][13][16].

Key Dates & Catalysts

  • Closes: January 01, 2027
Sources (16)
  1. 1Iran President Urges The U.S. To Return To Earlier Interim Peace Dealforbes.com
  2. 2Iran will reciprocate if US returns to Islamabad commitments, Pezeshkian says | Iran Internationaliranintl.com
  3. 3Iran urges US to comply with interim deal after Trump threatens further strikes | Quews Newsquews.news
  4. 4Iran President Says Tehran Would ‘Immediately’ Reciprocate if US Returns to June Dealenglish.aawsat.com
  5. 5WRAPUP 1-Iran urges US to comply with interim deal after Trump threatens further strikes | Internationaldevdiscourse.com
  6. 6Sanctions and bombs won’t end the war in Iran. Trump is running out of options against an intractable foetheconversation.com
  7. 7Kalshi traders are not expecting a U.S. and Iran nuclear...cnbc.com
  8. 8Kalshi traders see odds rising that a U.S.-Iran nuclear deal...cnbc.com
  9. 9The Iran War, Six Months In - The Soufan Centerthesoufancenter.org
  10. 10Analysis-After six months, the Iran war has reached its endgame - a costly stalemate - AL-MONITOR: The Middle Eastʼs leading independent news source since 2012al-monitor.com
  11. 11Iran war could last deep into 2027 as the Strait of Hormuz isn't that closed, allowing more oil out | Fortunefortune.com
  12. 12Possible U.S.-Iran Agreement: INARA and U.S. Sanctionscongress.gov
  13. 13Iran and Nuclear Weapons Productioncongress.gov
  14. 14U.S.-Iran Ceasefire and Negotiations: Assessment and...congress.gov
  15. 15U.S.-Iran Ceasefire and Negotiations: Assessment and Issues for Congresscongress.gov
  16. 16U.S. Conflict with Irancongress.gov