So, Senator Markwayne Mullin might be getting a promotion. The Oklahoma Republican, currently serving on the Senate Armed Services Committee, has been nominated by President Donald Trump to take over the Department of Homeland Security. It's a big job with a massive portfolio, from border security to cybersecurity. But before he potentially gets the keys to the DHS, there's another portfolio worth examining: his stock portfolio.

Mullin, 48, has been one of the most active stock traders in Congress since 2023, with over 500 transactions totaling more than $24 million in buys and sells. And some of those trades—particularly in defense and oil companies—have raised eyebrows, given his committee assignments and the timing of global events.

The Defense and Oil Playbook

Let's talk about the trades that look, well, interesting. Mullin owns stakes in major defense contractors like L3Harris Technologies (LHX) and RTX Corp (RTX). He's also bought shares in smaller companies with direct government ties, like VSE Corporation (VSEC), which has Air Force contracts, and Carpenter Technology (CRS), which makes specialty alloys for the defense industry.

On the energy front, he holds positions in Chevron Corporation (CVX) and ConocoPhillips (COP). Now, here's the thing: defense and oil stocks have been on a bit of a run. They got a boost after the U.S. attack on Iran and have remained elevated amid ongoing tensions in Venezuela, Russia, Ukraine, and the Middle East.

Buying stocks that benefit from geopolitical instability isn't illegal, of course. But when you're a member of the Senate Armed Services Committee—a group privy to non-public briefings on military strategy and global threats—people start to wonder. It creates at least the appearance of a conflict of interest, a potential use of inside information for personal gain. It's the kind of thing that makes good government advocates sigh heavily.

Going Magnificent (and Then Some)

Mullin isn't just betting on war and oil; he's also been loading up on America's corporate champions. In December, he went on a shopping spree in the tech sector, buying between $100,000 and $250,000 worth of shares in each of Apple Inc (AAPL), Amazon.com Inc (AMZN), Alphabet Inc (GOOGL), Microsoft Corporation (MSFT), and NVIDIA Corporation (NVDA). He also picked up $50,000 to $100,000 in Meta Platforms (META). That's six of the so-called "Magnificent Seven" tech stocks in one go.

This followed a even larger purchase in November: $250,000 to $500,000 in Microsoft stock. It seems the senator has a strong belief in the long-term growth of big tech.

His interests are broad. He's also been acquiring shares in financial heavyweights like Citigroup (C), Goldman Sachs (GS), Mastercard (MA), JPMorgan (JPM), and American Express (AXP). And he holds positions in smaller companies like FirstCash Holdings (FCFS), Stride (LRN), and the aforementioned VSE Corporation.

The Numbers Behind the Trades

With an estimated net worth of $66 million, Mullin has the capital to be an active investor. His trading history since 2023 breaks down like this:

• 2023: Bought $5.18 million in stocks, sold $163,000.
• 2024: Bought $3.7 million, sold $5.29 million.
• 2025: Bought $4.66 million, sold $3.15 million.
• 2026 to date: Bought $975,000, sold $886,000.

The data shows a pattern of significant buying activity, with over $14.5 million in purchases against roughly $9.5 million in sales. In total, that's the over $24 million in transaction value across more than 500 trades.

This isn't Mullin's first brush with controversy over his finances. In 2025, he violated the Stop Trading on Congressional Knowledge (STOCK) Act by failing to properly disclose transactions he made back in 2023 until two years later. The law is supposed to promote transparency and prevent insider trading by requiring timely reporting. A late filing is a violation, plain and simple.

Confirmation Road Ahead

All of this is likely to come up when Mullin sits for his confirmation hearings to lead the DHS. Senators will probably ask pointed questions about whether his personal investments could influence his decision-making on national security matters. Can someone who profits from defense contractors objectively oversee agencies that contract with them?

But here's the political reality: Mullin is probably going to be confirmed. The Republican Party holds majorities in both the House and Senate. There's a longstanding tradition in Congress of being, let's say, accommodating to former colleagues during confirmation hearings. The scrutiny might be intense for a day or two, but the path to approval is relatively clear.

So, we're left with a familiar Washington story. A powerful lawmaker with access to sensitive information is also an active stock picker, making moves that align suspiciously well with world events. He's broken the rules on disclosure before. And now he's in line for a job that gives him even more insight into the levers of power and profit. It's the kind of thing that makes you wonder how the game is really played.