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Correlation Analysis

BERKSHIRE HATHAWAY Class B vs First Solar, Inc.

BRK.B vs FSLR

+0.636

Moderate positive

When one moves up, the other tends to follow.

BRK.B logo

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

FSLR logo

First Solar, Inc.

FSLR

First Solar designs and manufactures solar photovoltaic panels, modules, and systems for use in utility-scale development projects. The company's solar modules use cadmium telluride to convert sunlight into electricity. This is commonly called thin-film technology. First Solar is the world's largest thin-film solar module manufacturer. It has production lines in Vietnam, Malaysia, the United States, and India.

Market cap 21B · 7,900 employees

Apr 9, 2021 — Apr 7, 2026Daily1,254 data pointsStockStock

Time Series

Relative Performance

Green: BRK.BGray: FSLR36 of 1,254 points (sampled)

Who Moves First

FSLR leads BRK.B by 6 days

FSLR tends to move before BRK.B.

After testing 13 timing shifts, the strongest relationship was +0.639 (they moved in the same direction).

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

+0.178

11 periods · Return correlation when both series rose

Both Falling

+0.336

5 periods · Return correlation when both series fell

Diverging

-0.591

19 periods · Return correlation when series moved apart

R-Squared

40.5%

Share of variance in one series explained by the other.

Trend Agreement

55.3%

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: [0.602, 0.668]

Scatter

XY Regression

247250300350400450500522.151.1100150200250297.1BERKSHIRE HATHAWAY Class BFirst Solar, Inc.Data pointsFit (r = 0.636)

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

BRK.B logo

BERKSHIRE HATHAWAY Class B

BRK.B

Market cap 1T

Stock · 1,254 raw → 1,254 prepared

Series B

FSLR logo

First Solar, Inc.

FSLR

Market cap 21B · 7,900 employees

Stock · 1,254 raw → 1,254 prepared

Sign agreement

100.0%

How often both values share the same sign.

Zero crossings

29

Estimated crossover points between normalized spreads.

Slope

0.4268

Linear regression slope.

Intercept

-3.3148

Linear regression intercept.

Related Extremes

Highest and Lowest Correlated

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