Correlation Analysis
BERKSHIRE HATHAWAY Class B vs CPIAUCSL
BRK.B vs CPIAUCSL
+0.873
Very strong positive
When one moves up, the other tends to follow.
BERKSHIRE HATHAWAY Class B
↗BRK.B
Berkshire Hathaway is a holding company with a wide array of subsidiaries engaged in diverse activities. The firm's core business segment is insurance, run primarily through Geico, Berkshire Hathaway Reinsurance Group, and Berkshire Hathaway Primary Group. Berkshire has used the excess cash thrown off from its operations to acquire Burlington Northern Santa Fe (railroad), Berkshire Hathaway Energy (utilities and energy distributors), and the companies that make up its manufacturing, service, and retailing operations (which include Precision Castparts, Lubrizol, Clayton Homes, Marmon, and IMC/ISCAR). The conglomerate is unique in that it is run on a completely decentralized basis. Berkshire is expected to generate close to $375 billion in revenue in 2025.
Market cap 1T
CPIAUCSL
CPIAUCSL
Who Moves First
CPIAUCSL leads BRK.B by 5 months
CPIAUCSL tends to move before BRK.B.
Best correlation after shifting: +0.874 (13 shifts scanned)
Stability
Rolling Correlation
How the correlation evolves over time. A stable line means the relationship is reliable; large swings signal regime-dependent behavior.
Do They Crash Together?
Correlation by Market Regime
How these series behave when markets are rising, falling, or diverging. A correlation that holds in drawdowns is very different from one that only works in rallies.
Both Rising
-0.081
23 periods · Return correlation when both series rose
Both Falling
N/A
0 periods · Return correlation when both series fell
Diverging
-0.677
12 periods · Return correlation when series moved apart
R-Squared
76.3%
Share of variance in one series explained by the other.
Trend Agreement
68.4%
How often both series moved in the same direction period-to-period.
Overlap Quality
58
Thin shared window — 58 usable pairs.
Significance
p < 0.001
95% CI: [0.794, 0.923]
Time Series
Rebased to 100
Scatter
XY Regression
Pipeline
Data quality details
Pipeline
Data quality details
Pipeline Summary
58 paired observations survived the monthly window.
Raw input
1,254
949
Normalized
1,254
949
Prepared
61
949
Aligned
58
58
Invalid removed
0
A: 0 / B: 0
Duplicates removed
0
A: 0 / B: 0
Alignment drops
894
A: 3 / B: 891
Series A
BERKSHIRE HATHAWAY Class B
BRK.B
Market cap 1T
Stock · 1,254 raw → 61 prepared
Series B
CPIAUCSL
FRED · 949 raw → 949 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
1
Estimated crossover points between normalized spreads.
Slope
0.1778
Linear regression slope.
Intercept
236.5276
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 4 hours ago · ID: stock-brk-b-vs-fred-cpiaucsl-monthly-20260408-k91bav