Correlation Analysis
Costco Wholesale Corp vs NRG Energy, Inc.
COST vs NRG
+0.878
Very strong positive
When one moves up, the other tends to follow.
Costco Wholesale Corp
↗COST
Founded in 1983, Costco Wholesale now operates a global chain of membership-based warehouse clubs, delivering high-quality goods and services at consistently low prices. As of its most recent fiscal year, Costco operated approximately 910 warehouses, serving more than 80 million members across its three geographic segments: Costco US (approximately 73% of total revenue), Costco Canada (13%), and Costco International (14%).Costco's core value proposition—quality products at unbeatable prices—has yielded consistently strong member renewal rates (93% in the US and Canada and nearly 90% internationally). About 55% of Costco's fiscal 2025 revenue came from its grocery offerings, and another 25% from general merchandise.
Market cap 451.9B
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
Time Series
Relative Performance
Who Moves First
COST leads NRG by 6 days
COST tends to move before NRG.
After testing 13 timing shifts, the strongest relationship was +0.881 (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
+0.298
17 periods · Return correlation when both series rose
Both Falling
+0.801
6 periods · Return correlation when both series fell
Diverging
-0.539
12 periods · Return correlation when series moved apart
R-Squared
77.0%
Share of variance in one series explained by the other.
Trend Agreement
58.0%
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: [0.864, 0.890]
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
Costco Wholesale Corp
COST
Market cap 451.9B
Stock · 1,254 raw → 1,254 prepared
Series B
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
3
Estimated crossover points between normalized spreads.
Slope
0.1882
Linear regression slope.
Intercept
-55.7820
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 9 hours ago · ID: stock-cost-vs-stock-nrg-daily