Warren Buffett Remains Berkshire's Largest Individual Shareholder, With Forbes Pegging His Personal Fortune at About $149 Billion as of Mid-November. Here's Why Record Buybacks Are Quietly Growing His Stake Further.

Berkshire Hathaway (NYSE:BRKA) (NYSE:BRKB) sports a huge market capitalization of $1.3 trillion. Unsurprisingly, its single largest shareholder is Warren Buffett. Before stepping down as CEO and chairman of the board, he led the conglomerate for six decades, growing it into one of the world's most valuable companies.

As of Nov. 11, Forbes said the Oracle of Omaha had a net worth of $149 billion. This makes him the ninth-richest person on the face of the planet. Most of the others in the top 10 made their fortunes in the technology sector. While his peers bet on moonshot projects, Buffett created his wealth from buying existing businesses, with a philosophy centered on shrewd capital allocation, risk management, and operational prowess.

Even now, Buffett's net worth equals nearly 12% of Berkshire Hathaway's market capitalization — and stock buybacks are quietly increasing that stake, although there is also an opposing force at play.

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A busy Q3

The market remains focused on the artificial intelligence (AI) trade, which isn't a surprise given that this trend involves some of the most dominant and high-profile businesses on Earth. But investors have still prized Berkshire Hathaway, which is putting together a strong year. In 2026, its shares have climbed 17%. The gains came in the past few weeks. Since the beginning of October, the conglomerate’s stock has soared 18%.

Now the valuation doesn't look so attractive. Shares trade at a price-to-book ratio of well over 1.6. The five-year average is just under 1.5, so today's reading carries an 11% premium. I don't think value investors are rushing to buy the stock, especially since the multiple has expanded by 14% in one month.

Greg Abel, the current chief executive officer, must have viewed the valuation favorably before the stock's run, though. During the third quarter, he oversaw Berkshire Hathaway repurchasing $9.6 billion worth of its own stock. This comes after $4.5 billion in buybacks during Q2. In 2025, when the stock traded at an average P/B multiple of 1.6, zero shares were repurchased.

Nonetheless, this capital allocation decision reduces the number of outstanding shares. Aside from dividends, which this business doesn't pay, buybacks are the primary means of returning cash to shareholders. Existing investors see their individual stakes increase, as their claim on company profits rises.

In the past 10 years, Berkshire Hathaway reduced its Class B outstanding share count by 13%. If it weren't for his philanthropic efforts, Warren Buffett's ownership percentage would have grown. The stock has risen by 277% in the past decade, boosting the Oracle of Omaha's net worth.

Massive cash drag

Many of the best companies out there conduct share repurchases. Apple (NASDAQ:AAPL) is a prime example. Of the $102 billion in capital it returned to investors in fiscal 2026 (ended Sept. 26), 85% was allocated to stock buybacks. And this business has been a huge winner for investors over the years.

Investors might not be as familiar with AutoZone (NYSE:AZO). The retailer sells aftermarket automotive parts through a network of over 8,000 stores and has consistently repurchased its own stock for decades. Over the past 10 years, it shrunk its outstanding share count by a jaw-dropping 45%. And the stock is up 334% over that time.

These two examples shouldn't automatically encourage investors to only buy these sorts of companies. Buybacks are a clear indicator that the leadership team is focused on its shareholders. But it can also reveal that the list of growth opportunities is limited.

That's the best way to describe Berkshire Hathaway today. As of Sept. 30, it had $352 billion in cash on the balance sheet. This will remain a drag on its ability to increase its intrinsic value. Abel and Buffett would much rather that money be allocated to high-return opportunities.

Neil Patel has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Apple and Berkshire Hathaway. The Motley Fool has a disclosure policy.