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RiskModels / 13F Filers / Berkshire Hathaway

Berkshire Hathaway · Warren Buffett

Latest 13F holdings with ERM3 risk decomposition — how much of the portfolio's return is market beta versus genuine stock-picking, and where the residual risk concentrates.

Reported AUM
$287.6B
Holdings
28
Top-10 weight
91%
As of
2026-06-30
Filed
2026-08-14

Return attribution — beta or stock-picking?

Sum of monthly ERM3 attribution over the trailing 12 months (2025-07-31 → 2026-06-30), modeled subset of holdings. Roughly 37% of the gross return came from stock selection (residual return) — most of the return came from factor exposure, not selection.

Gross

+17.3%

Market

+14.6%

Sector

-4.3%

Subsector

+0.7%

Stock selection

+6.3%

Top holdings

28 reported positions; top 15 shown. “Stock-specific” is the share of each position's variance not explained by market, sector, or subsector factors.

#HoldingWeightValueStock-specific
1AAPLApple Inc.22.9%$66.0B86%
2AXPAmerican Express Company17.8%$51.3B47%
3KOCoca-Cola Company11.3%$32.5B53%
4GOOGLmodeled on GOOGAlphabet Inc.9.8%$28.2B60%
5BACBank of America Corp9.6%$27.5B40%
6CVXChevron Corporation4.9%$14.0B22%
7OXYOccidental Petroleum Corporation4.5%$12.9B33%
8MCOMoody's Corporation3.9%$11.2B68%
9GOOGAlphabet Inc. Class C3.3%$9.6B60%
10KHCKraft Heinz Company2.7%$7.7B68%
11DVADaVita Inc.2.2%$6.4B96%
12DALDelta Air Lines, Inc.1.9%$5.4B55%
13SIRISiriusXM Holdings Inc.1.3%$3.7B94%
14VRSNVeriSign, Inc.0.8%$2.3B89%
15KRKroger Co.0.8%$2.2B67%

90% of reported AUM is in the ERM3 model universe; attribution and risk shares cover that subset. Source: SEC Form 13F-HR, filed 2026-08-14.

How concentrated is this book?

Quarter-end concentration across 53 filings from 2013-06-30 to 2026-06-30, with the latest filing set against this manager's own median.

Effective N
8.0
median 5.6
Top 5 weight
—
no median
Top 10 weight
90.7%
median 91.2%
Weight HHI
—
no median

Effective N is inverse-Herfindahl breadth, not a holding count: it falls well below the number of positions when one name dominates, which is the case worth seeing. This book held 28 positions at 2026-06-30.

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Informational use only — not investment advice. Blue Water Macro Corp.