Buffett Breaks the 10% Ceiling: Berkshire Crowned Mitsubishi’s Biggest Shareholder (feat. Berkshire Hathaway, Mitsubishi Corp, Warren Buffett, Japan trading houses, Mitsui, Itochu, Marubeni, Sumitomo)

What if the quietest move on Wall Street just happened in Tokyo?
Who dares to cross the sacred 10% line in Japan’s corporate world?
And why is Warren Buffett—the man who usually bets on Coca-Cola and Apple—suddenly obsessed with century-old Japanese trading giants?

This isn’t just another investment story. It’s a play that rattles the rules, bends the law’s spotlight, and flips the script on global power plays. Stay tuned—because what just happened with Mitsubishi isn’t business as usual. It’s Buffett rewriting the rulebook.

Stake Shake, Buffett’s Break

1. Mitsubishi Corp.’s biggest shareholder just changed hands (feat. Japan’s mega trading houses and Berkshire).
2. Berkshire Hathaway raised its stake in Mitsubishi from 9.75% to 10.2%, making it the largest shareholder.
3. The purchase was done under National Indemnity’s name, but since that’s a fully owned Berkshire unit, it’s really Buffett calling the shots.

Five Alive, Stakes That Thrive

4. Berkshire’s positions in Japan’s big five trading houses now stand at: Mitsubishi 10.2%, Mitsui 9.82%, Itochu 8.53%, Marubeni 9.30%, and Sumitomo 9.29%.
5. Back in March, the numbers were smaller—Mitsubishi was still under 10%, and the rest were in the 7–9% range. For the first time, Mitsubishi cracked the 10% barrier.
6. Mitsui itself confirmed Berkshire has been adding more shares.
7. And the vibe is that the other trading houses could soon jump past 10% too.

Buffett’s Letter, Japan Gets Better

8. On February 22, 2025, Berkshire Hathaway’s annual shareholder letter hit the press.
9. In it, Warren Buffett spotlighted the Japanese trading houses:
10. “A small but important exception to our U.S.-focused investing is our growing positions in Japan. Nearly six years ago, we started buying into these five: Itochu, Marubeni, Mitsubishi, Mitsui, and Sumitomo. They remind me of Berkshire—diverse, disciplined, and successful. They hold businesses across industries, many in Japan but also worldwide.
11. We first invested in July 2019, amazed at how cheap the stocks were. Over time, our trust has grown. Greg Abel has met with them often, and I’ve followed their progress. We admire their capital discipline, their leadership, and their treatment of shareholders.
12. They raise dividends when it makes sense, buy back stock reasonably, and their executive pay is modest compared to U.S. firms.
13. We plan to hold these stakes for decades and back their boards. At first, we pledged to stay under 10%. But as we got close, the companies agreed to ease the cap. So you’ll likely see Berkshire’s stakes increase over time.
14. I expect Greg and his successors to keep these positions for decades, and that Berkshire will find productive ways to collaborate with them in the future.”
15. Two key takeaways: Berkshire plans to hold these stakes for decades, and it’s ready to push above 10%.
16. That second part—going over 10%—is exactly what just got confirmed.

Ten Percent, Big Event

12. Hitting 10% matters: under Japanese law, foreign investors who cross that line must file a notice and disclose it publicly.
13. Once word gets out, retail traders can pile in, driving up the buy price.
14. Buffett clearly knew this but still decided to push past 10%—and spelled it out in his shareholder letter.

Market Spark, Stocks Leave a Mark

15. After Berkshire’s February 22 announcement, the trading houses’ stock prices started to rally.
16. Marubeni jumped from 2,289 yen to 3,293 yen—up 47%.
17. Itochu rose from 6,141 yen to 8,321 yen—up 36%.
18. Sumitomo climbed from 3,228 yen to 4,119 yen—about 28%. Most of the others saw similar gains around the same time.

Mitsubishi’s Fresh Twist on the List

19. In April 2025, Mitsubishi announced its long-term plan, “Business Strategy 2027.”
20. Two big shifts stand out: first, it’s scaling back renewables.
21. The company said it’s suspending three offshore wind projects.
22. Second, it’s moving deeper into food.
23. In July 2025, Mitsubishi bought Norway’s Grieg Seafood’s fish-farming business for $1 billion and boosted its stake in Thai Union Group, the tuna giant, from 6% to 20%.
24. Honestly, not a bad direction at all.

Buffett’s Map, But Who Drives After the Gap?

Berkshire Hathaway is still steering firmly along the road Buffett paved. The real question isn’t about today—it’s about tomorrow. When Buffett is no longer in the driver’s seat, will the company keep cruising with the same wisdom… or take a wrong turn?