Short Answer

The model sees potential mispricing for the Supreme Court shielding Monsanto from Roundup failure-to-warn lawsuits before August 2026. It assigns a 55.7% probability for the 'Before 2026' outcome, notably lower than the market's 67.0%, suggesting the market may be overestimating this possibility.

1. Executive Verdict

  • The Supreme Court heard arguments on Roundup failure-to-warn claims.
  • Monsanto argues FIFRA preempts state-law failure-to-warn claims.
  • A ruling in Monsanto v. Durnell is expected this summer/early July.
  • No consensus analyst estimate exists for Bayer's total Roundup liability.
  • The Supreme Court Database provides justice voting data on preemption cases.
  • Legal analysts interpret oral arguments to predict the preemption ruling.

Who Wins and Why

Outcome Market Model Why
Before 2026 67.0% 55.7% The Supreme Court may consider a petition related to Monsanto's liability before 2026.

Current Context

The Supreme Court is currently considering a critical Roundup warning label case. The Court granted certiorari on January 16, 2026, in Monsanto Co. v. Durnell (No. 24-1068), and heard arguments on April 27, 2026 [^][^][^]. The case specifically addresses whether the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) preempts state-level, label-based failure-to-warn claims when the Environmental Protection Agency (EPA) has not mandated such a warning [^][^][^]. A ruling in favor of Monsanto's argument regarding FIFRA preemption could potentially block thousands or tens of thousands of existing Roundup failure-to-warn lawsuits, depending on the scope of the preemption outlined by the Court [^][^][^].
The Supreme Court's decision is anticipated by early July 2026. PBS (reporting AP) expects a decision by the end of June, while SCOTUSblog projects early July [^][^]. If the decision is released in late June or early July 2026, its ramifications are expected to significantly impact the legal landscape throughout August 2026 [^][^]. This timeline coincides with ongoing parallel settlement activity related to Roundup lawsuits, where the opt-out deadline for a proposed settlement was June 4, and a final approval hearing is scheduled for July 9 [^][^].

2. Market Behavior & Price Dynamics

Historical Price (Probability)

Outcome probability
Date
This market, which asks if the Supreme Court will shield Monsanto from certain lawsuits, opened with a high probability of a "YES" outcome, starting at 75%. However, the price has since followed a consistent downward trend, falling to a low of 67%. This decline in perceived probability occurred in the weeks following the Supreme Court's oral arguments on April 27, 2026. The initial high price suggests that traders anticipated a favorable ruling for Monsanto, but as analysis of the justices' questions and debate became available, sentiment appears to have shifted. The sustained drop from 75% to 67% indicates that the market is reassessing the likelihood of a Monsanto victory, pricing in a greater chance that state-level failure-to-warn claims will not be preempted by federal law.
The total trading volume of 2,805 contracts suggests moderate but meaningful engagement from participants. The price has established a clear range between a high of 82% and a low of 67%. The current price of 67% is acting as a support level, a price floor that the market has not yet broken through. Conversely, the 75% opening price and the 82% peak represent key resistance levels that the market has moved away from. Overall, the price action reflects a clear erosion of confidence in a "YES" resolution. The market sentiment has moved from strongly favoring a ruling for Monsanto to one of greater uncertainty, though it still indicates a "YES" outcome is more likely than not.

3. Market Data

View on Kalshi →

Contract Snapshot

The market resolves to Yes if the Supreme Court rules in Monsanto Company v. Durnell that the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) preempts state-law, label-based failure-to-warn claims where the EPA has not required the warning. It resolves to No if the Court holds such claims are not preempted. The market also resolves to No if the case is dismissed, settled, or otherwise disposed of without a merits decision on whether FIFRA preempts such claims, with all outcomes required to occur before the market closes by August 1, 2026, at 10:00am EDT.

Available Contracts

Market options and current pricing

Outcome bucket Yes (price) No (price) Last trade probability
Before 2026 $0.71 $0.30 67%

Market Discussion

The Supreme Court heard oral arguments on April 27, 2026, in "Monsanto Company v. Durnell" to determine if federal law preempts state-level "failure-to-warn" claims regarding Roundup's glyphosate [^][^][^]. While a ruling for Monsanto could shield the company and other pesticide manufacturers from similar lawsuits, the decision is considered "too close to call" following justices' questioning during arguments, which shifted prediction market sentiment [^][^]. In a related development, Bayer-Monsanto announced a proposed $7.25 billion settlement in early 2026 for Roundup cancer lawsuits, viewed as a hedge against the Supreme Court's impending decision [^][^][^].

4. How might the outcome of Monsanto v. Durnell impact the final approval of the separate Roundup class-action settlement scheduled for July 2026?

Supreme Court Oral ArgumentsApril 27, 2026 [^][^]
Settlement Preliminary ApprovalMarch 4, 2026 [^][^][^]
Settlement Amount$7.25 billion [^]
The Supreme Court recently heard arguments impacting Roundup failure-to-warn claims. Oral arguments were held on April 27, 2026, in the case of Monsanto v. Durnell, which will determine whether the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) preempts state-law failure-to-warn claims regarding Roundup [^][^][^]. The ultimate outcome of this case creates significant uncertainty for the final approval of a separate, substantial class-action settlement related to Roundup [^].
A separate Roundup class-action settlement faces conditional final approval. This $7.25 billion Roundup class-action settlement received preliminary approval from a Missouri court on March 4, 2026, with the final approval hearing scheduled for July 9, 2026 [^][^][^]. However, Bayer maintains the option to withdraw from this agreement. This decision is contingent upon two main factors: the Supreme Court’s eventual ruling in Monsanto v. Durnell, and the number of plaintiffs who opt out of the settlement by the June 4, 2026, deadline [^].

5. What is the consensus analyst estimate for Bayer's total financial liability from Roundup lawsuits if the Supreme Court rules against Monsanto?

Potential liability reduction (SCOTUS rules for Bayer)$787 million [^]
Bayer's reserve for outstanding suits$11.25 billion [^][^]
Prediction market probability (SCOTUS shields Monsanto)69% [^]
No consensus analyst estimate exists for Bayer's Roundup liability post-Supreme Court ruling. While a direct consensus estimate for Bayer's total financial liability from Roundup lawsuits, specifically if the Supreme Court rules against Monsanto, is not available, related financial insight exists. Bloomberg Intelligence analyst Holly Froum estimated that if the Supreme Court rules in favor of Bayer on the failure-to-warn preemption issue, approximately $787 million of existing Roundup verdicts could be affected [^]. This figure represents a potential liability reduction linked to a favorable Supreme Court ruling for Bayer [^].
Bayer has reserved significant funds to manage its existing Roundup litigation. The company has previously set aside $11.25 billion to address approximately 65,000 outstanding lawsuits [^][^]. Additionally, a prediction market indicates a 69% crowd-sourced probability that the Supreme Court will ultimately shield Monsanto from these lawsuits [^]. However, this market specifically focuses on predicting the legal outcome and does not directly quantify the potential dollar liability [^].

6. How do Monsanto's and Durnell's legal briefs compare on the key issue of FIFRA's preemption of state failure-to-warn claims?

Monsanto's ArgumentFIFRA 7 U.S.C. § 136v(b) preempts state failure-to-warn claims (in addition to or different from federal standards) [^][^][^]
Durnell's ArgumentClaim is not preempted as it is a 'parallel requirement' consistent with FIFRA's misbranding prohibition, citing Bates v. Dow AgroSciences LLC [^][^][^]
Case StatusCharacterized as 'too close to call' after oral arguments on April 27, 2026 [^][^]
Monsanto argues FIFRA preempts state-law failure-to-warn claims. The core dispute between Monsanto and John Durnell centers on whether the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), specifically 7 U.S.C. § 136v(b), expressly and impliedly preempts state-law failure-to-warn claims. Monsanto contends that such claims would impose labeling requirements "in addition to or different from" federal standards, which require EPA approval [^][^][^]. Monsanto further notes that the EPA has consistently found glyphosate to be non-carcinogenic [^][^][^].
Durnell counters that his claim is a permissible parallel requirement. John Durnell, conversely, argues his failure-to-warn claim is not preempted because it constitutes a "parallel requirement" consistent with FIFRA’s prohibition against misbranding [^][^]. Durnell supports his position by referencing Bates v. Dow AgroSciences LLC, 544 U.S. 431 (2005), to establish that state-law tort claims are permissible when they align with federal misbranding regulations [^][^][^].
The Supreme Court case outcome remains uncertain, called "too close to call." Following oral arguments held on April 27, 2026, observers have described the case as "too close to call" [^][^].

7. What data is available on how individual Supreme Court justices have voted in federal preemption cases during the Roberts Court era?

Primary Data SourceThe Supreme Court Database (SCDB) [^][^][^]
Type of Data AvailableJustice-centered data with individual vote records [^][^]
Supplemental ResearchPublished empirical study on statutory federal preemption [^][^]
The Supreme Court Database provides key justice-centered voting data. This primary resource offers detailed information on how individual Supreme Court justices have voted in federal preemption cases during the Roberts Court era. The SCDB utilizes "Justice Centered data," where each row documents a justice's participation and vote in a particular dispute [^][^].
SCDB variables allow detailed analysis of individual justice voting behavior. The database's documentation and codebook outline various voting and opinion variables crucial for this analysis. These include "The Vote in the Case," "Direction of the Individual Justice’s Votes," and "Majority and Minority Voting by Justice" [^][^]. These variables make it possible to construct justice-by-justice roll-calls once the data is filtered for preemption issues or specific legal provisions. Current releases, such as the 2024 and 2025 versions, can be utilized to compute individual-justice preemption voting rates relevant to the Roberts Court era [^][^][^].
An empirical study further supports analysis of justice voting patterns. This published research explicitly compares statutory federal preemption in the Rehnquist and Roberts Courts. It offers additional data and analysis while examining individual justices' voting records, providing a detailed look into their decisions in preemption cases [^][^].

8. How are legal analysts interpreting the oral arguments in Monsanto v. Durnell to predict the Supreme Court's ruling on FIFRA preemption?

Decision anticipated byAugust 2026 [^][^][^][^]
Chance of Monsanto ruling (Oct 2025)70% [^][^][^][^]
Durnell's jury award$1.25 million [^][^]
The Supreme Court will likely decide on FIFRA preemption for state-law warnings. The Court's ruling in Monsanto v. Durnell, anticipated before August 2026, will center on whether state-law duties to warn are considered "additional to or different from" federal labeling requirements [^][^][^][^]. Monsanto contends that state-mandated warnings would violate federal provisions because the Environmental Protection Agency (EPA) approved Roundup's labels without a cancer warning. The company argues it cannot unilaterally add a warning without EPA approval, and such a warning would contradict federal determinations, given the EPA's position that glyphosate is not carcinogenic [^][^]. A prediction market in October 2025, before oral arguments, indicated forecasters assigned a 70% chance that the Supreme Court would rule in favor of Monsanto [^][^][^][^].
Durnell argues state failure-to-warn claims align with federal misbranding standards. Richard Durnell, who received $1.25 million from a Missouri jury after alleging Roundup caused his non-Hodgkin's lymphoma, asserts his state-law "failure-to-warn" claim is consistent with FIFRA [^][^]. His legal team highlights FIFRA's provisions against misbranding and inadequate warnings, suggesting that a state-law duty to warn is not "in addition to or different from" existing federal requirements [^][^][^]. Durnell also disputes Monsanto's assertion that the EPA would have rejected a cancer warning, arguing Monsanto never presented "clear evidence" of such a rejection or even submitted such a warning for review [^]. This position aligns with the precedent set in Dow Agrosciences, which established that state common law claims are not preempted by FIFRA if they function as an equivalent to FIFRA's misbranding standard, demanding adequate warnings [^][^][^]. The ultimate decision holds significant consequences for thousands of ongoing Roundup lawsuits and the wider field of toxic tort litigation [^][^][^].

9. What Could Change the Odds

Key Catalysts

The Supreme Court heard oral arguments in Monsanto Company v. Durnell on April 27, 2026 [^][^], with a ruling expected "this summer/early July" [^]. A decision favoring Monsanto could support the preemption of state failure-to-warn claims linked to EPA-approved labels that lack a cancer warning [^]. Bayer/Monsanto's litigation strategy explicitly relies on FIFRA preemption, as the company states that a favorable Supreme Court ruling on federal preemption could largely halt Roundup™ litigation by preventing state-based failure-to-warn claims from proceeding when the EPA approved the Roundup label without a cancer warning [^][^][^].
Conversely, advocacy suggests that an outcome favoring Monsanto could deny a "right to sue," remove incentives for chemical companies to update warnings, and substantially reduce the ability of plaintiffs to pursue Roundup failure-to-warn claims [^] . This perspective notes that the Court's 2005 decision rejected the industry's earlier shield argument [^]. Additionally, a proposed nationwide Roundup class settlement, valued at $7.25 billion and announced by Bayer, has a June 4 deadline for participation or opting out [^][^][^][^]. The timing of this settlement can be affected by the Supreme Court decision, which is expected around early July [^].

Key Dates & Catalysts

  • Expiration: August 01, 2026
  • Closes: August 01, 2026

10. Decision-Flipping Events

  • Trigger: The Supreme Court heard oral arguments in Monsanto Company v.
  • Trigger: Durnell on April 27, 2026 [^] [^] , with a ruling expected "this summer/early July" [^] .
  • Trigger: A decision favoring Monsanto could support the preemption of state failure-to-warn claims linked to EPA-approved labels that lack a cancer warning [^] .
  • Trigger: Bayer/Monsanto's litigation strategy explicitly relies on FIFRA preemption, as the company states that a favorable Supreme Court ruling on federal preemption could largely halt Roundup™ litigation by preventing state-based failure-to-warn claims from proceeding when the EPA approved the Roundup label without a cancer warning [^] [^] [^] .

12. Historical Resolutions

No historical resolution data available for this series.