Where is this manager's return actually coming from — replicable market and sector exposure, or stock selection? Pulled live from the latest 13F and decomposed through the ERM3 cascade. The stock-selection residual — the return remaining after the model's specified market, sector, and subsector exposures — is the component that persists out of sample.
Modeled AUM
$251.9B
Holdings
28
Top-10 weight
92%
Modeled AUM is the sum of disclosed long US equity positions that join the ERM3 universe — not firm-wide AUM. 13F books omit shorts, most derivatives, and non-US holdings.
Evidence
13F · disclosed-long analysis
Holdings as of
2026-03-31
Filed
2026-06-14
Model
ERM3 v3.0
Form 13F discloses long US positions only, on a delayed filing schedule; short positions and most derivatives are not reported.
Selection signature
Exposure-driven
16% of BERKSHIRE HATHAWAY INC's risk is stock-specific over the full monthly history of the reported 13F book — the structural read. Stock selection added 29% of the trailing return (which swings with the window). The rest is buyable market, sector, and style exposure — a descriptive read, not a recommendation.
Risk decomposition
77%
16%
MarketSectorSubsectorStyle tiltResidual risk
At a glance
Selection signature
16% of risk
Exposure-driven
Replicable exposure
84%
Mostly buyable
Mandate style
Large Blend
Multi-style
Concentration
eff. N 7.9
Concentrated
Peer rank · Mega tier
#31 / 419
Return attribution
AIBERKSHIRE HATHAWAY INC's +11.0% trailing-year return was led by market beta (+17.0% market); stock selection contributed -3.2%.
Layer
Detail
1M
3M
6M
1Y
Gross return
total realized
-1.4%
-1.9%
+2.4%
+11.0%
− Market
broad-market beta
-3.4%
-3.0%
-1.0%
+17.0%
− Sector
sector timing
+0.5%
+3.4%
+3.3%
2 · Stock-selection residual
The stock-selection residual — return left after market, sector, subsector, and style are stripped away. This is the component the research shows persists out of sample (forward Q5−Q1 +2.3pp, t≈3.4), while sector- and style-timing do not.
Stock-selection return
-3.2%
trailing, gross — residual after market / sector / subsector
Residual risk share
33%
stock-specific share of monthly portfolio variance · trailing 12 months
Return from selection
29%
of gross return this window
Out-of-sample persistence
+2.3pp · t≈3.4
forward Q5−Q1 across the study cohort — not this manager
Gross ranking signal within mandate; net-of-fee outcomes depend on fees and implementation. Not a claim of net-of-fee outperformance. See the evidence →
4 · Mandate fit
Dominant style
Large Blend
Style concentration (HHI)
0.42
Effective styles
2.4
Effective N (positions)
7.9
5 · Peer context
#31 / 419
In the Mega AUM cohort by aum erm3 (1m).
94% of reported AUM is in the ERM3 model universe; attribution and residual shares cover that sleeve.
Run this on your managers
This is a live example. Send us a roster — 13F managers or your own holdings sleeves — and we'll return a Manager Skill Review and a board-ready IC memo for each. Print or PDF this page for the memo format.
Live data from SEC Form 13F via the RiskModels ERM3 model, filed 2026-06-14. Figures are gross, holdings-derived, and within-mandate. Informational use only — not investment advice.
Manager Skill Review · Live example
BERKSHIRE HATHAWAY INC
Where is this manager's return actually coming from — replicable market and sector exposure, or stock selection? Pulled live from the latest 13F and decomposed through the ERM3 cascade. The stock-selection residual — the return remaining after the model's specified market, sector, and subsector exposures — is the component that persists out of sample.
Modeled AUM
$251.9B
Holdings
28
Top-10 weight
92%
Modeled AUM is the sum of disclosed long US equity positions that join the ERM3 universe — not firm-wide AUM. 13F books omit shorts, most derivatives, and non-US holdings.
Evidence
13F · disclosed-long analysis
Holdings as of
2026-03-31
Filed
2026-06-14
Model
ERM3 v3.0
Form 13F discloses long US positions only, on a delayed filing schedule; short positions and most derivatives are not reported.
Selection signature
Exposure-driven
16% of BERKSHIRE HATHAWAY INC's risk is stock-specific over the full monthly history of the reported 13F book — the structural read. Stock selection added 29% of the trailing return (which swings with the window). The rest is buyable market, sector, and style exposure — a descriptive read, not a recommendation.
Risk decomposition
77%
16%
MarketSectorSubsectorStyle tiltResidual risk
At a glance
Selection signature
16% of risk
Exposure-driven
Replicable exposure
84%
Mostly buyable
Mandate style
Large Blend
Multi-style
Concentration
eff. N 7.9
Concentrated
Peer rank · Mega tier
#31 / 419
Return attribution
AIBERKSHIRE HATHAWAY INC's +11.0% trailing-year return was led by market beta (+17.0% market); stock selection contributed -3.2%.
Layer
Detail
1M
3M
6M
1Y
Gross return
total realized
-1.4%
-1.9%
+2.4%
+11.0%
− Market
broad-market beta
-3.4%
-3.0%
-1.0%
+17.0%
− Sector
sector timing
+0.5%
+3.4%
+3.3%
2 · Stock-selection residual
The stock-selection residual — return left after market, sector, subsector, and style are stripped away. This is the component the research shows persists out of sample (forward Q5−Q1 +2.3pp, t≈3.4), while sector- and style-timing do not.
Stock-selection return
-3.2%
trailing, gross — residual after market / sector / subsector
Residual risk share
33%
stock-specific share of monthly portfolio variance · trailing 12 months
Return from selection
29%
of gross return this window
Out-of-sample persistence
+2.3pp · t≈3.4
forward Q5−Q1 across the study cohort — not this manager
Gross ranking signal within mandate; net-of-fee outcomes depend on fees and implementation. Not a claim of net-of-fee outperformance. See the evidence →
4 · Mandate fit
Dominant style
Large Blend
Style concentration (HHI)
0.42
Effective styles
2.4
Effective N (positions)
7.9
5 · Peer context
#31 / 419
In the Mega AUM cohort by aum erm3 (1m).
94% of reported AUM is in the ERM3 model universe; attribution and residual shares cover that sleeve.
Run this on your managers
This is a live example. Send us a roster — 13F managers or your own holdings sleeves — and we'll return a Manager Skill Review and a board-ready IC memo for each. Print or PDF this page for the memo format.
Live data from SEC Form 13F via the RiskModels ERM3 model, filed 2026-06-14. Figures are gross, holdings-derived, and within-mandate. Informational use only — not investment advice.
-2.6%
− Subsector
industry timing
+0.4%
-0.1%
-0.1%
+0.6%
= Buyable exposure
replicable in ETFs
-2.6%
+0.3%
+2.2%
+15.0%
Stock selection (residual return)
net of market/sector/subsector · cohort evidence: persists OOS
+1.3%
-1.8%
+0.4%
-3.2%
Risk attribution
AI16% of the book's risk is stock-specific; the rest is broad-market (77%) and sector exposure.
Layer
Detail
Full
Recent
− Market
broad-market beta
77%
35%
− Sector
sector exposure
6%
31%
− Subsector
industry exposure
1%
0%
= Buyable exposure
replicable
83%
67%
Residual risk share
stock-specific share of variance — where selection can show up