Bayer’s stock rose after the U.S. Supreme Court agreed to hear an appeal related to Roundup

Bayer AG shares rose more than 7% on Monday after the U.S. Supreme Court agreed to hear the German group’s appeal in a pivotal Roundup weedkiller case, fueling optimism that a favorable decision could reduce the company’s long-standing legal burden.

The U.S. Supreme Court said on Friday it will consider whether federal pesticide regulations override state-level failure-to-warn lawsuits when the Environmental Protection Agency has not mandated cancer warnings for glyphosate-based products.

The case, known as Durnell, stems from an October 2023 Missouri jury ruling that found Monsanto—acquired by Bayer in 2018—did not adequately warn consumers about alleged cancer risks linked to Roundup, awarding $1.25 million in damages. Other allegations were dismissed, and the jury declined to impose punitive damages. A Missouri appeals court upheld the verdict in 2025.

Bayer argues that permitting such claims weakens the EPA’s authority, noting the agency has repeatedly determined that glyphosate is unlikely to cause cancer in humans and has approved Roundup labeling without cancer warnings. The U.S. Solicitor General has supported Bayer’s stance, warning that the Missouri decision could allow juries to overrule federal scientific judgments.

Investors viewed the Supreme Court’s move as a possible inflection point in litigation that has burdened Bayer’s valuation since its $63 billion purchase of Monsanto.

Sources: Reuters