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Correlation Analysis

BERKSHIRE HATHAWAY Class B vs NRG Energy, Inc.

BRK.B vs NRG

+0.882

Very strong 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

NRG logo

NRG Energy, Inc.

NRG

NRG Energy is one of the largest retail energy providers in the US, with 6 million customers. Vivint Smart Home, which NRG acquired in 2023, has 2 million home-services customers. NRG also is one of the largest US independent power producers, with 13 gigawatts of coal, gas, and oil power generation capacity primarily in Texas. The LS Power asset acquisition adds 13 GW of gas-fired power plants mostly in the Eastern US. NRG exited Chapter 11 bankruptcy as a stand-alone entity in December 2003.

Market cap 31.8B · 16,702 employees

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

Time Series

Relative Performance

Green: BRK.BGray: NRG36 of 1,254 points (sampled)

Who Moves First

BRK.B leads NRG by 6 days

BRK.B tends to move before NRG.

After testing 13 timing shifts, the strongest relationship was +0.887 (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

-0.157

14 periods · Return correlation when both series rose

Both Falling

N/A

4 periods · Return correlation when both series fell

Diverging

-0.705

17 periods · Return correlation when series moved apart

R-Squared

77.7%

Share of variance in one series explained by the other.

Trend Agreement

61.2%

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: [0.869, 0.893]

Scatter

XY Regression

247250300350400450500522.121406080100120140160180184.4BERKSHIRE HATHAWAY Class BNRG Energy, Inc.Data pointsFit (r = 0.882)

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

NRG logo

NRG Energy, Inc.

NRG

Market cap 31.8B · 16,702 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

0.4805

Linear regression slope.

Intercept

-109.7089

Linear regression intercept.

Related Extremes

Highest and Lowest Correlated

Saved 6 hours ago · ID: stock-brk-b-vs-stock-nrg-daily