CorrlensCorrlens
Correlate

Correlation Analysis

BERKSHIRE HATHAWAY Class B vs CoStar Group Inc

BRK.B vs CSGP

-0.126

Weak inverse

When one moves up, the other tends to move down.

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

CSGP logo

CoStar Group Inc

CSGP

CoStar Group is a leading provider of commercial real estate data and marketplace listing platforms. Its data offering contains in-depth analytical information on over 5 million commercial real estate properties related to various subsectors spanning office, retail, hotels, multifamily, healthcare, industrial, self-storage, and data centers. It operates many well-respected brands such as CoStar Suite, LoopNet, Apartments.com, BizBuySell, and Lands of America, with more than 75% of its revenue classified as subscription-based. The company recently expanded its presence into Canada, the United Kingdom, Spain, and France.

Market cap 17.3B · 8,000 employees

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

Time Series

Relative Performance

Green: BRK.BGray: CSGP36 of 1,254 points (sampled)

Who Moves First

BRK.B leads CSGP by 6 days

BRK.B tends to move before CSGP.

After testing 13 timing shifts, the strongest relationship was -0.134 (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

+0.248

9 periods · Return correlation when both series rose

Both Falling

+0.033

8 periods · Return correlation when both series fell

Diverging

-0.517

18 periods · Return correlation when series moved apart

R-Squared

1.6%

Share of variance in one series explained by the other.

Trend Agreement

62.3%

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: [-0.181, -0.072]

Scatter

XY Regression

247250300350400450500522.135.140506070809099.2BERKSHIRE HATHAWAY Class BCoStar Group IncData pointsFit (r = -0.126)

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

CSGP logo

CoStar Group Inc

CSGP

Market cap 17.3B · 8,000 employees

Stock · 1,254 raw → 1,254 prepared

Sign agreement

100.0%

How often both values share the same sign.

Zero crossings

1

Estimated crossover points between normalized spreads.

Slope

-0.0158

Linear regression slope.

Intercept

82.5844

Linear regression intercept.

Related Extremes

Highest and Lowest Correlated

Saved 7 hours ago · ID: stock-brk-b-vs-stock-csgp-daily