Berkshire Hathaway Inc. Class B (BRK-B)
Daily ERM3 factor decomposition: how much of BRK-B's variance is explained by the market, its sector, and its subsector — and the ETF notionals that would neutralize each layer.
- Price
- $514.95
- Market cap
- $725.3B
- 23-day vol
- 11.0%
- Sector proxy
- XLF
- Subsector proxy
- KIE
Risk DNA
28% of BRK-B's variance is systematic (explainable by market, sector, and subsector factors); the rest is stock-specific.
BRK-B carries 69% stock-specific risk against a peer average of 67% — more of what happens here is specific to this name than is typical for its cohort.
Market (-5.1%) covaried negatively with BRK-B over this window, offsetting its variance rather than adding to it. Clamped to 0% for the bar and the remaining layers renormalized, so the percentages above sum to 100.
ETF hedge ratios
Dollars of ETF to short per $1 of BRK-B held — executable hedge weights, not regression betas. L1 hedges market only; L3 adds sector and subsector layers.
| Level | Market (SPY) | Sector (XLF) | Subsector (KIE) | Explained risk |
|---|---|---|---|---|
| L1 | $-0.07 | — | — | -5.1% |
| L2 | $0.31 | $-0.62 | — | 20.5% |
| L3 | $0.15 | $-0.33 | $-0.32 | 27.9% |
Data as of September 15, 2026. Updated daily from the ERM3 pipeline.
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