Correlation Analysis
Costco Wholesale Corp vs Westlake Corporation
COST vs WLK
-0.029
Near-zero inverse
When one moves up, the other tends to move down.
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
Westlake Corporation
↗WLK
Westlake Corp is a vertically integrated international manufacturer and marketer of both housing and infrastructure products and performance and essential materials that are designed to enhance the lives of people every day. Its Performance and Essential Materials segment offers a wide range of essential building blocks for making products utilized in everyday living, including olefins, vinyl chemicals, polyethylene, and epoxies. Its Housing and Infrastructure Products segment produces key finished goods for building products, pipe and fittings, and international compounds businesses.
Market cap 15.3B · 14,600 employees
Time Series
Relative Performance
Who Moves First
COST leads WLK by 6 days
COST tends to move before WLK.
After testing 13 timing shifts, the strongest relationship was -0.045 (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
+0.598
11 periods · Return correlation when both series rose
Both Falling
+0.809
6 periods · Return correlation when both series fell
Diverging
-0.591
18 periods · Return correlation when series moved apart
R-Squared
0.1%
Share of variance in one series explained by the other.
Trend Agreement
56.5%
How often both series moved in the same direction period-to-period.
Overlap Quality
1,254
Deep shared window — 1,254 usable pairs.
Significance
n.s.
95% CI: [-0.084, 0.026]
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
Westlake Corporation
WLK
Market cap 15.3B · 14,600 employees
Stock · 1,254 raw → 1,254 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
7
Estimated crossover points between normalized spreads.
Slope
-0.0032
Linear regression slope.
Intercept
112.4828
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 7 hours ago · ID: stock-cost-vs-stock-wlk-daily