New DHS Secretary Markwayne Mullin Faces Scrutiny Over Stock Trading and Potential Conflicts as He Takes Over Agency
Sen. Markwayne Mullin (R-Okla.) was sworn in as the new Secretary of the Department of Homeland Security on March 24-25, 2026, following his Senate confirmation in a 54-45 bipartisan vote. He replaces Kristi Noem, whom President Donald Trump fired earlier in March amid criticism of a $220 million taxpayer-funded advertising campaign that featured Noem prominently.
Mullin, a former plumber, businessman, and mixed martial arts fighter, brings a significant personal fortune to the role. His net worth has grown dramatically since entering Congress in 2013 — from between $2.8 million and $9 million in 2012 to an estimated range of $29 million to $97 million (with some analyses placing it around $65-66 million) by 2024-2025, according to financial disclosure forms.
Much of that increase stems from active stock trading. The New York Times reported that Mullin has become one of the most prolific stock traders in Congress. In late 2025, he invested as much as $2.8 million across 31 companies in a single day. His portfolio includes holdings in defense and technology firms with significant contracts to the Department of Homeland Security, such as Microsoft, RTX, L3Harris, and VSE Corporation (which handles aircraft maintenance and repair).
Specific examples include:
- Purchasing up to $100,000 in L3Harris shares in 2025, after which the stock rose 65% (compared to 13% overall market growth in the same period).
- Investing in Chevron on December 29, 2025 — the only major U.S. oil company producing in Venezuela — just days before Trump publicly pressured Venezuela on oil terms. Chevron’s stock subsequently surged while the broader market declined.
Experts who reviewed the trades, including Dartmouth economist Bruce Sacerdote, found no clear evidence of insider trading. They described the timing as potentially “blind luck.” Federal law currently allows members of Congress to trade stocks, even in sectors they oversee, though this has drawn growing bipartisan criticism.
Watchdog groups like Public Citizen have raised concerns about the appearance of conflicts, especially as Mullin now leads an agency with a budget that ballooned to nearly $190 billion and is awarding billions in new contracts for immigration enforcement, border security, and related operations. Mullin has held shares worth up to $2 million in companies with notable DHS ties.
A White House spokeswoman stated that Secretary Mullin “will comply with all ethics and conflict of interest rules, just as every cabinet secretary does.”
The timing of Mullin’s confirmation adds another layer. Noem’s ouster centered on accusations of self-promotion and potential favoritism in the expensive DHS ad campaign, which some lawmakers from both parties viewed as wasteful and self-serving. Critics now question whether Mullin’s extensive stock holdings and trading history raise similar red flags for an agency responsible for massive government contracting.
Bipartisan calls have grown in recent years for stricter limits on stock trading by members of Congress and cabinet officials to avoid even the perception of using non-public information or prioritizing personal investments.
Mullin’s background as a successful business owner (including Mullin Plumbing and a cattle ranch) has been praised by supporters as proof of his understanding of American entrepreneurship. Detractors argue his rapid wealth accumulation while in public office warrants closer ethics review given his new oversight role.
As the Department of Homeland Security continues to navigate a partial government shutdown and implements the administration’s immigration priorities, all eyes will be on how Secretary Mullin manages potential conflicts and leads one of the largest and most critical federal agencies.
By Sam Michael Follow us on X @realnewshubs and subscribe for push notifications
Follow and subscribe us for push notifications to never miss breaking updates.