Correlation Analysis
BERKSHIRE HATHAWAY Class B vs Interactive Brokers Group, Inc. Class A Common Stock
BRK.B vs IBKR
+0.884
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
Interactive Brokers Group, Inc. Class A Common Stock
↗IBKR
Interactive Brokers is a large, automated, retail and institutional brokerage that boasted nearly $780 billion in customer equity at the end of 2025. The company cut its teeth as a market maker, introducing US financial markets to automated and algorithmic training before expanding into brokerage services in 1993. The firm has a wide-ranging client base, with its best-in-class order execution and extremely low margin lending rates catering to a sophisticated audience of hedge funds, proprietary traders, and introducing brokers that account for about 45% of the firm's commissions. With operations spanning more than 160 electronic exchanges, 36 countries, and 28 currencies, Interactive Brokers caters to a global clientele, with more than 80% of active accounts sitting outside the US.
Market cap 30.6B · 3,182 employees
Time Series
Relative Performance
Who Moves First
BRK.B leads IBKR by 6 days
BRK.B tends to move before IBKR.
After testing 13 timing shifts, the strongest relationship was +0.886 (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
+0.069
14 periods · Return correlation when both series rose
Both Falling
+0.108
6 periods · Return correlation when both series fell
Diverging
-0.566
15 periods · Return correlation when series moved apart
R-Squared
78.2%
Share of variance in one series explained by the other.
Trend Agreement
60.2%
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: [0.871, 0.896]
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
Interactive Brokers Group, Inc. Class A Common Stock
IBKR
Market cap 30.6B · 3,182 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
0.1934
Linear regression slope.
Intercept
-41.9048
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
IBKR
Interactive Brokers Group, Inc. Class A Common Stock
Highest
+0.976
Walmart Inc. Common Stock
WMT · 1,254 data points
Lowest
+0.482
Johnson & Johnson
JNJ · 1,254 data points
Saved 7 hours ago · ID: stock-brk-b-vs-stock-ibkr-daily