If you're a member of Congress trading stocks, people are going to watch. Senator Markwayne Mullin (R-Okla.) knows this better than most. He's one of the most tracked lawmakers for his trading disclosures, a scrutiny that intensified after he held oil and defense stocks ahead of the attack on Iran. Now, as President Donald Trump's nominee to lead the Department of Homeland Security, the spotlight isn't dimming.

Here's a curious twist in his financial story: a slice of his investment portfolio looks eerily familiar to anyone who follows the Oracle of Omaha. Mullin currently owns 10 stocks that are also held by Berkshire Hathaway (BRK-A)/Berkshire Hathaway (BRK-B), the conglomerate built by legendary investor Warren Buffett.

It's not a perfect copy—Berkshire's portfolio is enormous and includes decades-old positions—but the overlap is significant. It raises a fun question: what does a sitting senator, trading frequently, see in the same companies as the world's most famous buy-and-hold investor?

The 10-Stock Club

Berkshire's portfolio is a mix of legacy holdings and newer additions. Mullin's shared picks, based on his disclosures since 2023, run the gamut from Berkshire's very largest bets to its smaller positions.

Let's break them down.

Apple Inc. (AAPL): This is the big one. Apple is Berkshire's largest holding, worth a staggering $57.0 billion and making up 18.6% of its stock portfolio. Mullin is clearly a fan too, having bought Apple stock four times in the last three years. His most recent purchase was for $100,000 to $250,000 in December 2025.

American Express (AXP): Another cornerstone of the Berkshire fortress. AmEx is Berkshire's second-largest holding at $44.6 billion (14.5% of the portfolio). Mullin has bought it three times since 2023, with his latest trade being a $1,000 to $15,000 purchase in December 2025.

Coca-Cola Inc. (KO): The quintessential Buffett stock. Coke is Berkshire's third-largest holding, worth $30.4 billion and accounting for 9.9% of the portfolio. Mullin has also bought it three times, including a $15,000 to $50,000 purchase in December 2025.

Chevron Corporation (CVX): The energy giant is Berkshire's fourth-largest holding at $25.9 billion (8.4%). Mullin bought $15,000 to $50,000 worth in both December 2025 and May 2025, though he has sold previous holdings in the oil stock.

Visa Inc. (V): Here we move into Berkshire's smaller, but still substantial, positions. Berkshire owns about $2.5 billion in Visa, making up 0.8% of its portfolio. Mullin bought shares twice in late 2023.

Constellation Brands (STZ): The beer and wine company is a $2.0 billion position for Berkshire (about 0.6%). Mullin's relationship with it is more active: he sold $15,000 to $50,000 worth in February 2025 (listed as a partial sale) after buying shares in 2023.

Mastercard (MA): A peer to Visa, Mastercard is a $1.9 billion holding for Berkshire (around 0.5%). Mullin has been a buyer, with purchases in December 2025, October 2023, and September 2023.

UnitedHealth Group (UNH): The health insurance titan is a $1.4 billion position for Berkshire (about 0.5%). Mullin bought shares in February 2026 and September 2025, after having sold a portion of earlier 2023 purchases.

Capital One Financial (COF): The credit card issuer is a $1.3 billion stake for Berkshire (roughly 0.4%). Mullin has been a consistent buyer, with three purchases in 2025 totaling between $80,000 and $250,000.

Amazon.com Inc. (AMZN): The e-commerce and cloud behemoth is a relatively small bet for Berkshire at $477.7 million (about 0.2% of the portfolio). Mullin, however, has gone bigger, buying Amazon stock four times since 2023. His largest purchase was $100,000 to $250,000 in December 2025.

Two Investors, Two Worlds

So they own some of the same stuff. But the "how" and "why" couldn't be more different. This is where the story gets interesting.

Warren Buffett, who stepped down as CEO of Berkshire at the end of 2025, built his legend on value investing and holding stocks "forever." His purchases in companies like Coke and AmEx are measured in decades, not days. The Berkshire portfolio is a monument to patience.

Senator Mullin operates on a different clock. According to reports, he has bought and sold $24 million in stock since 2023, executing over 500 trades. His recent activity includes buying shares of small-cap companies and making large purchases of many of the "Magnificent Seven" tech stocks. This is active trading, not a decades-long buy-and-hold.

This activity has drawn specific criticism. His portfolio has included oil and defense stocks—sectors that could benefit from the geopolitical shock of the Iran war. As a member of the Senate Armed Services Committee, these holdings raise obvious conflict-of-interest questions that watchdogs have flagged.

The takeaway? You can arrive at the same destination by very different roads. Mullin and Berkshire both own Apple, American Express, and Coca-Cola. For Berkshire, these are foundational pillars held with glacial patience. For a senator trading hundreds of times in a few years, they are pieces in a much more fluid and actively managed puzzle—one that happens to include some of the market's most iconic names.

It's a reminder that even when portfolios overlap, the strategies behind them can tell completely different stories.