Berkshire ekes out some new highs, but October rally stalls

Berkshire Hathaway shares ended October up 8.9%, versus a 0.9% decline for the S&P 500 and a 5.3% drop for the Nasdaq, as investors rotated away from AI and technology stocks. Berkshire's Alphabet stake fell from a Q3 high of $40 billion to $29.6 billion after Alphabet shares plunged nearly 13% Thursday, amid negative free cash flow of $9.1 billion and weaker-than-expected search revenue. Berkshire also disclosed a $69 million DaVita share sale, part of quarterly trims to keep its stake at or below 45% under a 2024 agreement.

Analysis

The rotation into Berkshire is a relative-flow signal, not yet evidence of a durable earnings re-rating. After strong relative performance, chasing Berkshire here risks buying the defensive trade after it has already attracted attention; its cash balance may cushion drawdowns, but does not by itself establish attractive forward returns. Over the next 1–3 months, the key event is Berkshire’s updated portfolio disclosure: the June 30 share count makes the reported Alphabet exposure stale, and the filing may clarify whether Berkshire used the selloff to add, hold, or reduce. A further reduction would weaken the “Buffett conviction” narrative; an increase would support it, but still would not resolve Alphabet’s operating risk.

For Alphabet, the market’s concern is the combination of elevated AI investment and possible search substitution. If AI features shift queries without preserving monetizable ad engagement, higher infrastructure spending could pressure both cash generation and the multiple; if usage monetizes or capex intensity moderates, the current reaction may prove excessive. The next few quarters’ search-ad growth, capex, and free-cash-flow conversion matter more than one quarter’s spend. Six to 18 months out, this is a competitive-economics question, not simply an AI sentiment trade.

DaVita’s Berkshire sales appear tied to maintaining the agreed ownership ceiling, not a fresh fundamental signal. However, required selling as DaVita buys back shares can offset some of the float reduction investors expect from repurchases. Treat it as a potential flow headwind, not a standalone short thesis; earnings and guidance are the falsifiers.

Key Decisions for Investors

• Avoid chasing Berkshire’s recent relative strength. Consider a small, defined-risk long Berkshire/short Nasdaq-100 pair only if tech weakness persists and Berkshire holds its relative trend; exit if the spread reverses materially or Berkshire’s operating outlook weakens.
• Keep Alphabet exposure tactical rather than treating Berkshire’s position as validation. Wait for the next filing and upcoming results; monitor search-ad growth, AI-related capex, and free-cash-flow conversion before adding. Sustained search deceleration alongside rising capex would support further downside; improving monetization and cash conversion would invalidate it.
• Do not read Berkshire’s DaVita trims as a change in conviction. Track DaVita buyback pace against Berkshire’s required sales and upcoming guidance; avoid a directional DVA trade unless fundamentals deteriorate independently of the ownership-agreement flow.