Scan: US x China tariff agreement by December 31?

date	predicted	market price	confidence
2026-08-27	84%	85%	62%
2026-08-20	86%	92%	56%

1. Planner Fable 5.1 · Fermi decomposition + tool plan

Tools chosen: polymarket_direct polymarket_related kalshi_related article_search claude_news gdelt_news court_docket wikipedia code_execution

Sub-questions (Fermi decomposition)

What is the current Polymarket YES price and how has it trended over the past 90 days?
When was this market created, and has any publicly announced mutual US-China tariff/trade agreement (e.g., truce extension, tariff reduction) been announced since creation that might already satisfy resolution?
Is a Trump-Xi summit (e.g., Trump's Beijing visit in spring 2026 or Xi's US visit) scheduled, and is credible reporting anticipating a formal trade/tariff deal at or around it?
When does the current one-year US-China trade truce (agreed Oct/Nov 2025) expire, and is a renewal/extension likely to be jointly announced before Dec 31, 2026?
How has the Supreme Court IEEPA tariff ruling (or other legal/legislative action) changed the US tariff structure on China, and does it increase or decrease the likelihood of a new mutual agreement?
What do related Kalshi and Polymarket markets (Trump-Xi meeting, China tariff levels, trade deal markets) imply about the probability of a deal in 2026?
Historically, how often have the US and China reached publicly announced mutual tariff agreements within a ~12-month window during active negotiation periods (2018-2020, 2025)?

Planner reasoning

This Polymarket question hinges on whether a new publicly announced mutual US-China tariff agreement occurs between market creation and end of 2026. Key drivers are the current market price, the status of the Busan/Geneva truce framework (one-year truce expiring ~Nov 2026), Trump's planned Beijing visit and any expected 'phase two' deal, and legal shocks like the SCOTUS IEEPA tariff ruling that could force renegotiation. I anchor on the direct market, triangulate with related Kalshi/Polymarket markets, and use news search to establish the negotiation timeline and whether a qualifying announcement has already occurred.

2. Research Parallel tool calls

tool	status	time	items	summary
polymarket_direct	OK	0.2s	1	## This Market's Polymarket Data US x China tariff agreement by December 31? - Current price (probability): 90.25% - 7-day price change: +2.60% - 30-day price change: -1.65% - Total volume: $255,931 (USD notional) - Price range: 83.50% - 92.20% - Data points: 90 days
polymarket_related	OK	0.5s	3	Polymarket search over 4 keyword(s), kept 3 matches. keyword 'China tariff': 1 markets \| keyword 'Trump Xi': 2 markets \| keyword 'US China trade deal': 0 markets \| keyword 'China trade': 0 markets
kalshi_related	OK	6.3s	3	3 related markets / summaries. keyword 'China tariff': ok \| keyword 'Trump Xi meeting': ok \| keyword 'China trade deal': ok
article_search	OK	46.7s	30	Fetched 30 unique articles across 4 queries (lookback=45d). 'US China tariff agreement 2026': 10 articles \| 'Trump Xi summit Beijing trade deal': 10 articles \| 'US China trade truce extension': 10 articles \| 'Supreme Court IEEPA tariffs China': 10 articles
claude_news	OK	24.1s	23	## Key Findings - Busan truce (Oct 30, 2025) established a one-year framework: At the APEC summit in South Korea, the U.S. lowered fentanyl-related tariffs on Chinese imports to 10%, down from 20%, and further extended its pause on heightened reciprocal tariffs on imports from China until Nov.
gdelt_news	OK	115.7s	30	GDELT: 30 articles across 4 queries (lookback=30d). 'US China tariff agreement': 10 hits \| 'Trump Xi trade deal': 10 hits \| 'China Ministry of Commerce tariffs US': error GDELT rate-limited after retries (429) \| 'US China trade truce': 10 hits
court_docket	OK	11.1s	5	Found 5 results for 'IEEPA tariffs Learning Resources V.O.S. Selections' (type=o).
wikipedia	OK	0.3s	3	Fetched 3 Wikipedia entries (1 missing pages).
code_execution	OK	41.0s	0	Base rate construction (rolling 12‑month windows during active US‑China tariff negotiation eras): - Agreement dates used: Dec 1 2018 (Buenos Aires truce), Jan 15 2020 (Phase One), May 12 2025 (Geneva truce), Jun 11 2025 (London framework), Aug 12 2025 (truce extension), Oct 30 2025 (Busan/K

3. Evidence Brief Sonnet 5 · 7114 chars

# Current state The US-China tariff relationship is governed by the Oct 30, 2025 Busan truce (a mutual agreement already announced), with rolling implementation deadlines (Nov 10, 2026 reciprocal-tariff suspension; Dec 31, 2026 China countermeasure suspension) falling inside this question's window. A second Trump-Xi summit is scheduled for Sept 24, 2026 in Washington (unconfirmed by China), with further meetings reportedly planned for November (Shenzhen) and December (G20 Miami). No comprehensive "phase two" final deal has been announced since Busan; the base case is continued rolling truces/frameworks rather than a single grand bargain, but the question's resolution bar (a "publicly announced mutual agreement" including lowered tariffs by both sides) has arguably already been met once by Busan and is very likely to be met again via truce renewal before Dec 31, 2026. # Timeline of key events - 2025-05 to 2025-08 (confirmed): Series of US-China truces/frameworks: Geneva (May 12), London framework (Jun 11), truce extension (Aug 12) — rapid negotiation cadence (~every 57 days). - 2025-10-30 (confirmed): Busan/APEC truce — US cuts fentanyl tariffs to 10%, extends reciprocal-tariff pause to Nov 10, 2026; China suspends retaliatory tariffs/countermeasures until Dec 31, 2026. Confirmed via White House fact sheet (Nov 2025). - 2026-02-20 (confirmed): Supreme Court rules IEEPA tariffs illegal (Learning Resources v. Trump), forcing pivot to Section 301/Section 122 authority. - 2026-05-13/15 (confirmed): First 2026 Trump-Xi summit in Beijing — new "board of trade"/"board of investment," China agrees to $17B/yr ag purchases + 200 Boeing jets; no major new tariff/tech deal ("architecture, not a grand bargain" — Model Diplomat). - 2026-07-23/24 (confirmed): USTR imposes 12.5% Section 301 tariff on all Chinese goods, replacing voided IEEPA tariffs. - 2026-08-06 to 09-17 (reported): Tit-for-tat frictions (chip tariffs, sanctions) raise doubts about September summit; US report on countries helping China dodge tariffs adds friction (BBC). - 2026-09-10 (reported, widely syndicated AP): China says it "hopes to agree with the US on tariff reductions at an early date" ahead of summit. - 2026-09-24 (scheduled, unconfirmed by China): Second Trump-Xi summit in Washington — framed by analysts (Heritage, CNBC) as "low-expectations," maintenance-only. - Late 2026 (reported/planned): Additional Trump-Xi meetings floated for November (Shenzhen) and December (G20 Miami), aligning with truce expiration deadlines. # Event Will the US and China officially/publicly announce a mutual tariff agreement between market creation and Dec 31, 2026? # Outcomes to forecast Yes / No # Kalshi market anchor No Kalshi-direct price returned for this ticker; Polymarket is the best available anchor: **YES 90.25%**, 7-day change +2.6%, 30-day change -1.65%, range 83.5%-92.2% over 90 days, volume ~$256K. Trend is modestly upward recently after a dip. # Resolution source No resolution_source tool result provided. # Sub-question answers 1. **Polymarket trend** — Currently 90.25% YES; up from a 90-day low of 83.5%, recent 7-day uptick (+2.6%) but slight 30-day pullback (-1.65%). [polymarket_direct] 2. **Prior qualifying agreement since creation** — Yes: the Oct 30, 2025 Busan truce is a publicly announced mutual agreement (mutual tariff cuts/suspensions), which may already satisfy resolution depending on exact market creation date and interpretation. [claude_news, whitehouse.gov] 3. **Summit anticipating a deal** — A second Trump-Xi summit is scheduled Sept 24, 2026 in Washington, but expectations are explicitly framed as low/"maintenance," not a breakthrough deal; further meetings reportedly planned Nov (Shenzhen) and Dec (G20 Miami). [Heritage, CNBC, Atlantic Council] 4. **Truce expiration/renewal** — US reciprocal-tariff suspension expires Nov 10, 2026; China's countermeasure suspension/exclusion process runs through Dec 31, 2026 — both fall inside the question window, creating natural renewal-announcement opportunities. [claude_news] 5. **IEEPA ruling impact** — SCOTUS struck down IEEPA tariffs (Feb 2026); US pivoted to Section 122 (expired Jul 24, 2026) then Section 301 (12.5% tariff, effective Jul 24, 2026), replacing prior authority. This legal churn increases the odds of fresh negotiated agreements to stabilize the new tariff structure. [court_docket, Wikipedia] 6. **Related markets** — Kalshi's "US-China FTA before 2029" trades only 15% (down from 40% 30-day range), and other Kalshi China markets are low-probability, but these track a much higher bar (formal FTA) than this question's "any mutual agreement" standard. [kalshi_related] 7. **Historical base rate** — Rolling 12-month windows during active negotiation eras (2018-19, 2025) show agreements landing ~94% of the time; strict same-calendar-year base rate ~67%. [code_execution] # Key facts 1. [claude_news/whitehouse.gov] Busan truce (Oct 30, 2025) is a confirmed, already-announced mutual tariff agreement. 2. [claude_news] May 2026 Beijing summit produced trade institutions/purchases but "no grand bargain." 3. [court_docket] SCOTUS invalidated IEEPA tariffs Feb 2026, forcing new tariff architecture (Section 301, 12.5%, effective Jul 24, 2026). 4. [gdelt_news] Sept 10, 2026: China publicly states it hopes to agree on tariff reductions "at an early date," ahead of Sept 24 summit. 5. [claude_news] Two key truce-related deadlines (Nov 10, Dec 31, 2026) fall within the question's resolution window. # Cross-market signals - Kalshi related: FTA-specific market at 15% (higher bar, not directly comparable); no direct Kalshi ticker price found for this exact event. - Polymarket: 90.25% YES, moderately rising. - Sportsbook implied: N/A. # Analyst opinions and speculation - Heritage/CNBC: September summit is "low-expectations," maintenance-focused, unlikely to produce a major new deal. - Model Diplomat/Atlantic Council: Relationship characterized as rolling "architecture" of truces, not a single comprehensive agreement — but this still may count under the question's broad "mutual agreement" language. # Directional lean per outcome - **Yes**: Strong — Busan truce already qualifies as a precedent event; high negotiation cadence in 2025-2026; two truce deadlines inside the window create natural renewal opportunities; base rate ~94% (rolling) supports high probability; Polymarket already at 90%. - **No**: Weak — requires total breakdown of talks, failure to renew any truce terms, and no incremental joint tariff announcement through 2026 despite multiple scheduled summits — historically rare in this cycle. # Gaps / unknowns - Exact market creation date unclear — determines whether Busan (Oct 30, 2025) counts as already satisfying resolution. - Whether Sept 24 Washington summit will happen/produce any joint tariff language remains unconfirmed by China. - No direct Kalshi ticker price retrieved for this specific market. # Calibration anchors - Polymarket YES 90.25% (anchor). - Historical rolling 12-month base rate ~94% (active negotiation era); strict calendar-year base rate ~67%.

4. Forecasters 5 draws · Fable 5.1 + GPT-5.6 Sol

claude-fable-5-1

56% conf

Yes	88%
No	12%

Polymarket anchors YES at ~90% with a modestly rising trend. The structural drivers favor YES: the US reciprocal-tariff suspension (Nov 10, 2026) and China's countermeasure suspension (Dec 31, 2026) both expire inside the window, forcing a renewal or replacement announcement, and three Trump-Xi meetings (Sept Washington, Nov Shenzhen, Dec G20) are scheduled around those deadlines. China's Sept 10 statement that it hopes to agree on tariff reductions 'at an early date' and the 2025-26 cadence of roughly bimonthly truces/frameworks support a ~94% rolling base rate. Residual NO risk comes from a possible breakdown after chip/sanction frictions and from resolution ambiguity about whether a mere truce extension counts as a 'mutual tariff agreement', so I shade slightly below the market.

claude-fable-5-1

60% conf

Yes	89%
No	11%

The Polymarket anchor sits at ~90% YES, and the structural setup strongly favors resolution: the US reciprocal-tariff suspension (Nov 10, 2026) and China's countermeasure suspension (Dec 31, 2026) both expire inside the window, creating near-mandatory renewal announcements, with Trump-Xi meetings scheduled for Sept 24, November (Shenzhen) and December (G20 Miami). China's Sept 10 statement that it hopes to agree on tariff reductions 'at an early date' and the rolling-truce cadence of 2025-26 (Geneva, London, Aug extension, Busan) point to at least one publicly announced mutual tariff arrangement before year-end; the Busan truce itself may already qualify depending on creation date. Residual risk comes from unclear resolution wording (whether a mere truce extension counts), the unconfirmed September summit amid chip/sanctions friction, and the possibility that deadlines are extended unilaterally rather than via a jointly announced deal. I stay close to the market anchor at ~0.89.

claude-fable-5-1

57% conf

Yes	89%
No	11%

The Polymarket anchor sits at 90.25% YES and has been range-bound 83-92% for 90 days, reflecting a consensus that some publicly announced mutual tariff agreement (truce renewal or new framework) will land by Dec 31, 2026. Two hard deadlines fall inside the window — the US reciprocal-tariff suspension (Nov 10) and China's countermeasure suspension (Dec 31) — and both sides have strong incentive to announce a renewal; China publicly said on Sept 10 it 'hopes to agree on tariff reductions at an early date,' and three Trump-Xi meetings (Sept, Nov, Dec) are scheduled or floated. The 2025-26 negotiation cadence (Geneva, London, Aug extension, Busan) shows agreements landing roughly every two months, supporting a ~94% rolling base rate. Main risks are resolution ambiguity (whether a mere truce extension counts, and the unknown market creation date relative to Busan), summit cancellation amid chip/sanction frictions, and the possibility that Trump lets deadlines lapse without a joint announcement, so I stay slightly below the market.

gpt-5.6-sol

74% conf

Yes	91%
No	9%

The 90.25% Polymarket YES price is the best available consensus anchor and is consistent with the high historical agreement rate during active negotiation periods. The confirmed Busan truce may already qualify, although the unknown market-creation date leaves material resolution risk. If it does not count, the Nov. 10 and Dec. 31 truce deadlines, China's stated interest in early tariff reductions, and several planned summits provide multiple opportunities for another qualifying announcement. Low expectations for the September summit and recent tariff friction prevent a more decisive YES forecast.

gpt-5.6-sol

69% conf

Yes	91%
No	9%

The 90.25% Polymarket YES price is the best available consensus anchor. The confirmed Busan truce may already qualify, while the November and December 2026 suspension deadlines and multiple planned summits provide further opportunities for even a limited renewal agreement. Low expectations for a comprehensive deal matter less because the apparent threshold is any publicly announced mutual tariff agreement, not a formal FTA. I move only slightly above the anchor because the market-creation date, resolution interpretation, and September summit status remain uncertain.

6. Final plain mean of 5 draws

90% (63% confidence)

Yes: 90% No: 10%

Mean of 5 draws (0.88, 0.89, 0.89, 0.91, 0.91). Polymarket anchors YES at ~90% with a modestly rising trend. The structural drivers favor YES: the US reciprocal-tariff suspension (Nov 10, 2026) and China's countermeasure suspension (Dec 31, 2026) both expire inside the window, forcing a renewal or replacement announcement, and three Trump-Xi meetings (Sept Washington, Nov Shenzhen, Dec G20) are scheduled around those deadlines. China's Sept 10 statement that it hopes to agree on tariff reductions 'at an early date' and the 2025-26 cadence of roughly bimonthly truces/frameworks support a ~94% rolling base rate. Residual NO risk comes from a possible breakdown after chip/sanction frictions and from resolution ambiguity about whether a mere truce extension counts as a 'mutual tariff agreement', so I shade slightly below the market.

Pipeline Timing

Total pipeline time: 191.9s

Per-tool research timings shown in the Research section above.