Bayer stock rises after Roundup trial win in St. Louis

What happened. A Missouri Circuit Court jury in St. Louis returned a unanimous verdict for Monsanto on Thursday, 29 October, in Theresa Aretino, et al. v. Monsanto Company. Monsanto belongs to Bayer. Three women, Theresa Aretino, Cynthia Fernandez and Betty Larkin, sued in 2020. They said they used Roundup regularly and later developed non-Hodgkin lymphoma. Fernandez died before the trial began. According to Bayer, the jury rejected the design defect, fraud and negligence claims.

Why this trial matters. In June 2026 the US Supreme Court ruled in Monsanto v. Durnell that the federal law FIFRA preempts state failure-to-warn claims when the US Environmental Protection Agency (EPA) has made a definitive safety determination. Reuters reports that makers must use the exact label the EPA approved. Before that, most lawsuits argued that Roundup's label had no cancer warning. The St. Louis plaintiffs relied on design defect and negligence instead. Bayer argues those claims are also closed by the Supreme Court ruling. Plaintiffs' attorneys disagree. Bayer calls this the first time a court has tested such arguments at trial.

What the sides say. Bill Dodero, Bayer's US general counsel, said the verdict should send a strong signal: after Durnell, plaintiffs will find it hard both to show their claims are viable and to present the evidence. The plaintiffs' attorneys did not immediately respond to Reuters late on Thursday. Bayer denies the claims and says decades of studies show glyphosate is safe. The EPA has previously concluded that glyphosate is probably not carcinogenic, but it is now running a new review. In 2015 the International Agency for Research on Cancer called it “probably carcinogenic”. Bayer says that is an outlier opinion based on flawed methodology.

What comes next, and the stock. Separately, Bayer is pursuing a $7.25 billion settlement of other cases. A Missouri state court judge in St. Louis is reviewing it, and there is no ruling yet. The three women are not part of the settlement. Bayer faces around 65,000 claims in the US in total. Bayer shares gained more than 4% on Xetra on Thursday. The first reports of the verdict appeared after the European market had closed, so Thursday's gain most likely is not about it (our inference from publication times). On Friday morning the stock rose at one point by 4.9% against the Xetra close to 50.31 euros on Tradegate. That comes from Goldesel, whose text is partly AI-generated, so the figures are early and not final. These are past moves, not a forecast.

What we don't know. When the St. Louis judge will rule on the settlement. How other courts and juries will treat such arguments. Whether the plaintiffs will appeal.

已确认的事实

• A Missouri Circuit Court jury in St. Louis returned a unanimous defense verdict for Monsanto, a Bayer unit, in Theresa Aretino, et al. v. Monsanto Company; the verdict came on Thursday, 29 October 2026.^[1][2]
• The jury found for Monsanto on the design defect, fraud and negligence claims that each of the three plaintiffs pursued at trial.^[1]
• Theresa Aretino, Cynthia Fernandez and Betty Larkin sued in 2020, saying they used Roundup regularly and later developed non-Hodgkin lymphoma; Fernandez died before the trial began.^[2]
• It was the first Roundup trial since the US Supreme Court ruling in Monsanto v. Durnell in June 2026.^[1][2]
• Under the Supreme Court ruling, the federal law FIFRA preempts state failure-to-warn claims when the EPA has made a definitive safety determination; Reuters adds that herbicide makers must use the exact label the EPA approved.^[1][2]
• Bayer has argued that design-defect and negligence claims are also foreclosed by the Supreme Court ruling, while plaintiffs' attorneys say those claims are not affected.^[2]
• Bill Dodero, Bayer's US general counsel and global head of litigation, said the verdict should send a strong signal that plaintiffs face significant challenges after Durnell, both in showing their claims are viable and in presenting the evidence to prove them.^[1][2]
• Bayer faces around 65,000 claims in US state and federal courts from people who say they developed cancer after using Roundup at home or on the job.^[2]
• Separately, Bayer is pursuing a $7.25 billion settlement of other Roundup cases, which a Missouri state court judge in St. Louis is reviewing; no ruling has been issued yet.^[2]
• The three women are not participating in Bayer's proposed settlement.^[2]
• Bayer has denied the claims and says decades of studies show glyphosate is safe; the EPA has previously concluded that glyphosate is probably not carcinogenic, but it is in the middle of a new safety review.^[2]
• In 2015 the International Agency for Research on Cancer concluded that glyphosate was “probably carcinogenic” to humans; Bayer says that is an outlier opinion based on flawed methodology.^[2]
• Bayer shares gained more than 4% on Xetra on Thursday and, on Friday morning, rose at one point by 4.9% against the Xetra close to 50.31 euros on Tradegate (Goldesel, an AI-assisted text).^[3]

影响

• 已确认A jury rejected design-defect, fraud and negligence claims in the first Roundup trial since the Supreme Court ruling.
• 我们的解读Friday morning's gain in the stock is tied to the verdict, while Thursday's gain most likely is not: the verdict reports came after Xetra closed.
• 我们的解读One verdict in a three-plaintiff case does not settle the remaining claims or the settlement.

仍未知

• When the St. Louis judge will decide on the $7.25 billion settlement.
• How other courts and juries will weigh such arguments.
• Whether the plaintiffs will appeal.

影响到谁

US, Germany, World. People who follow Bayer stock, the Roundup and glyphosate litigation, and the US Supreme Court's Durnell ruling

来源

1. Bayer (Business Wire): Monsanto unanimously wins first Roundup trial since U.S. Supreme Court decision 2026年10月30日 · 官方
2. Reuters: Bayer wins Roundup weedkiller cancer trial while awaiting settlement ruling 2026年10月30日 · 媒体
3. Goldesel: Bayer Aktie: Glyphosat-Sieg in Missouri stärkt Vergleichshoffnung 2026年10月30日 · 媒体