Correlation Analysis
BERKSHIRE HATHAWAY Class B vs West Pharmaceutical Services, Inc.
BRK.B vs WST
-0.547
Moderate inverse
When one moves up, the other tends to move down.
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
West Pharmaceutical Services, Inc.
↗WST
West Pharmaceutical Services is based in Pennsylvania and is a key supplier to firms in the pharmaceutical, biotechnology, and generic drug industries. West sells elastomer-based packaging components (including stoppers, seals, and plungers), nonglass containment solutions, and auto-injectors for injectable drugs, which include large-molecule biologics, peptides such as GLP-1 receptor agonists, and small-molecule drugs. The company reports in two segments: proprietary products (about 80% of total revenue) and contract-manufactured products (about 20% of total revenue). It generates approximately 55% of its revenue from international markets and 45% from the United States.
Market cap 18.5B · 10,800 employees
Time Series
Relative Performance
Who Moves First
BRK.B leads WST by 6 days
BRK.B tends to move before WST.
After testing 13 timing shifts, the strongest relationship was -0.560 (they moved in opposite directions).
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
+0.475
12 periods · Return correlation when both series rose
Both Falling
+0.042
5 periods · Return correlation when both series fell
Diverging
-0.590
18 periods · Return correlation when series moved apart
R-Squared
29.9%
Share of variance in one series explained by the other.
Trend Agreement
60.0%
How often both series moved in the same direction period-to-period.
Overlap Quality
1,254
Deep shared window — 1,254 usable pairs.
Significance
p < 0.001
95% CI: [-0.584, -0.507]
Scatter
XY Regression
Pipeline
Data quality details
Pipeline
Data quality details
Pipeline Summary
1,254 paired data points survived the daily window.
Raw input
1,254
1,254
Normalized
1,254
1,254
Prepared
1,254
1,254
Aligned
1,254
1,254
Invalid removed
0
A: 0 / B: 0
Duplicates removed
0
A: 0 / B: 0
Alignment drops
0
A: 0 / B: 0
Series A
BERKSHIRE HATHAWAY Class B
BRK.B
Market cap 1T
Stock · 1,254 raw → 1,254 prepared
Series B
West Pharmaceutical Services, Inc.
WST
Market cap 18.5B · 10,800 employees
Stock · 1,254 raw → 1,254 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
3
Estimated crossover points between normalized spreads.
Slope
-0.4235
Linear regression slope.
Intercept
482.2805
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
BRK.B
BERKSHIRE HATHAWAY Class B
Highest
+0.968
Republic Services Inc.
RSG · 1,254 data points
Lowest
-0.918
United Parcel Service, Inc. Class B
UPS · 1,254 data points
WST
West Pharmaceutical Services, Inc.
Highest
-0.168
Tesla, Inc. Common Stock
TSLA · 1,254 data points
Lowest
-0.580
Walmart Inc. Common Stock
WMT · 1,254 data points
Saved 6 hours ago · ID: stock-brk-b-vs-stock-wst-daily