United States Senator Markwayne Mullin of Oklahoma has drawn new scrutiny after reporting the purchase of up to $50,000 in Pentair (NYSE: PNR) on November 10, 2025.
The transaction, officially disclosed on December 5, 2025, marks Mullin’s first recorded investment in Pentair, a water-treatment and aquatic-systems manufacturer. The firm supplies the U.S. Fish and Wildlife Service through its subsidiary Pentair Aquatic Eco-Systems.
Notably, the timing and context of the Congress trade have raised concerns because Mullin serves on the Senate Appropriations Subcommittee on Interior, Environment, and Related Agencies.
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The panel oversees the Interior Department and the Fish and Wildlife Service, agencies that use equipment from Pentair’s federal contracting arm. The overlap between his official responsibilities and his personal financial activity is likely to intensify questions about the possible use of insider information.
Mullin’s suspicious stock trades
Meanwhile, this trade adds to a growing list of transactions that have made Mullin one of the most controversial traders in Congress. Throughout 2025, he executed a series of large stock purchases in sectors deeply connected to federal policy.
In September, he bought more than $81,000 in Intuitive Surgical (NASDAQ: ISRG), a major medical-device manufacturer, while sitting on committees shaping national health policy. Weeks later, he made one of his largest trades of the year by purchasing up to $500,000 in Microsoft (NASDAQ: MSFT) stock.
Earlier investments have also drawn attention. For instance, in 2024, he purchased a small stake in Sprouts Farmers Market, a move that later paid off after the stock surged roughly 200 percent.
Viewed together, these episodes suggest a pattern in which Mullin regularly trades companies operating in sectors under congressional oversight, often with significant financial upside.
As a result, there have been growing concerns that the lawmaker may be using privileged information to guide his trades. However, no wrongdoing from his end has been established.
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