Berkshire Hathaway stock slips 2 percent as valuation debate intensifies

Berkshire Hathaway stock (ISIN US0846707026) ended the last completed trading session with its Class B shares at USD 509.20 on the New York Stock Exchange on September 17, 2026, down 2.04 percent from the previous close, while valuation models for the conglomerate’s Class A stock point to a significantly higher fair value as of September 18, 2026.

Valuation gap between price and fair value

According to Simply Wall St on September 18, 2026, Berkshire Hathaway’s most followed intrinsic valuation narrative pegs fair value for the Class A share at USD 943,785.74, compared with a last close of USD 763,935.95 for that line.

This implies that, on that model, the Class A stock trades about 19 percent below the estimated fair value as of September 18, 2026, a gap that underpins the view among some long-term investors that the conglomerate remains fundamentally undervalued despite its long run-up in absolute share price levels.

Recent share price performance and trading data

Per data from the Dhan stock portal for the New York listing, Berkshire Hathaway Inc Class B (ticker BRK.B) opened at USD 518.95 on September 18, 2026, after a prior close at USD 519.80, and during that session traded in a range between a high of USD 520.00 and a low of USD 508.78, with a closing snapshot of USD 509.21 at 1:29 a.m. India Standard Time stamped for the NYSE reference price.

At that USD 509.21 level on September 18, 2026, the Class B share was down 10.59 points or 2.04 percent on the day compared with the previous close, according to Dhan, while two analysts in that overview split between Buy and Hold ratings, resulting in 50 percent Buy and 50 percent Hold recommendations for the stock.

Relative performance versus the broader market

According to Zacks Investment Research in a note dated September 17, 2026, Berkshire Hathaway B closed that session at USD 509.20, down 2.04 percent from the prior trading day, even as wider equity benchmarks recovered, highlighting the stock as a laggard in the short term.

Over the prior month to that September 17, 2026 close, Zacks reports that Berkshire Hathaway’s Class B shares gained 4.04 percent, outperforming the Finance sector, which lost 3.64 percent, and the S&P 500 index, which fell 2.85 percent over the same period, a quantified relative strength signal that may support the long-term case even as the stock shows day-to-day volatility.

Portfolio positioning and AI exposure

Beyond short-term price moves, current coverage emphasizes how Berkshire Hathaway’s capital allocation is evolving under Greg Abel’s leadership. As MSN summarized on September 17, 2026, roughly 30.6 percent of Berkshire Hathaway’s equity portfolio is concentrated in two large artificial-intelligence-linked holdings, Alphabet and another major technology name, underlining the conglomerate’s sizable indirect participation in AI growth.

MSN notes that in the first quarter of 2026 Berkshire Hathaway bought an additional 36.4 million shares of Alphabet, and that the company now holds 78.79 million Alphabet Class A shares and 27.18 million Alphabet Class C shares as of that report, making the Google parent one of Berkshire’s most important technology positions by market value and a key driver of long-term performance.

Leadership transition viewed through the market lens

Investor focus on Berkshire Hathaway’s strategy has intensified following the generational leadership handover from Warren Buffett to Greg Abel. A feature article on September 18, 2026 by The Motley Fool highlights that Abel, Buffett’s designated successor, is leaning heavily into an AI-driven future by reinforcing Berkshire Hathaway’s exposure to technology platforms such as Alphabet.

The same coverage points out that for more than half a century Buffett steered Berkshire Hathaway, and that the strategic tilt toward AI under Abel could alter the risk profile and growth trajectory of the traditionally value-oriented conglomerate, a factor investors are weighing when comparing the current share price around USD 509 for the B shares with valuation estimates near USD 943,786 for the A shares.

Risk considerations around concentration and market signals

One key risk discussed in recent commentary is concentration in a small number of mega-cap technology stocks. The MSN analysis on September 17, 2026 indicates that having 30.6 percent of Berkshire Hathaway’s portfolio tied to two AI-focused stocks increases dependence on that segment’s valuations, exposing Berkshire shareholders to any future drawdown in those names even though the conglomerate’s core insurance and energy operations are more diversified.

Additionally, an Asia market wrap by Saxo on September 18, 2026 noted Berkshire Hathaway as a notable laggard weighing on financials, underscoring how the stock’s short-term underperformance can influence sector indices, even if long-term fundamental narratives remain constructive.

Stock level and investor takeaway

As of the latest available NYSE data, Berkshire Hathaway Inc Class B shares traded around USD 509.21 on September 18, 2026, representing a 2.04 percent decline versus the prior close and reflecting modest short-term selling pressure despite the conglomerate’s strong long-term record and substantial exposure to AI-linked technology holdings.

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