Correlation Analysis
Costco Wholesale Corp vs The Southern Company
COST vs SO
+0.901
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
The Southern Company
↗SO
Southern is one of the largest utilities in the US. The company serves 9 million customers with vertically integrated electric utilities in three states and natural gas distribution utilities in four states. It owns 46 gigawatts of rate-regulated generating capacity, primarily for serving customers in Georgia, Alabama, and Mississippi. Subsidiary Southern Power owns 13 gigawatts of natural gas generation and renewable energy across the US and sells the electricity primarily under long-term contracts.
Market cap 109.3B · 29,800 employees
Time Series
Relative Performance
Who Moves First
COST leads SO by 6 days
COST tends to move before SO.
After testing 13 timing shifts, the strongest relationship was +0.905 (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
+0.284
13 periods · Return correlation when both series rose
Both Falling
-0.132
5 periods · Return correlation when both series fell
Diverging
-0.646
17 periods · Return correlation when series moved apart
R-Squared
81.3%
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: [0.891, 0.911]
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
The Southern Company
SO
Market cap 109.3B · 29,800 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
0.0456
Linear regression slope.
Intercept
45.2346
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 4 hours ago · ID: stock-cost-vs-stock-so-daily