Correlation Analysis
Costco Wholesale Corp vs DexCom, Inc.
COST vs DXCM
-0.572
Moderate 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
DexCom, Inc.
↗DXCM
DexCom designs and commercializes continuous glucose monitoring systems for diabetic patients. CGM systems serve as an alternative to the traditional blood glucose meter process, and the company is evolving its CGM systems to provide integration with insulin pumps from Insulet and Tandem for automatic insulin delivery. DexCom's CGMs are available through medical equipment distributors as well as retail pharmacies.
Market cap 24.3B · 11,100 employees
Time Series
Relative Performance
Who Moves First
COST leads DXCM by 6 days
COST tends to move before DXCM.
After testing 13 timing shifts, the strongest relationship was -0.587 (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
+0.358
14 periods · Return correlation when both series rose
Both Falling
+0.417
9 periods · Return correlation when both series fell
Diverging
-0.381
12 periods · Return correlation when series moved apart
R-Squared
32.7%
Share of variance in one series explained by the other.
Trend Agreement
60.5%
How often both series moved in the same direction period-to-period.
Overlap Quality
1,254
Deep shared window — 1,254 usable pairs.
Significance
p < 0.001
95% CI: [-0.608, -0.533]
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
DexCom, Inc.
DXCM
Market cap 24.3B · 11,100 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
-0.0652
Linear regression slope.
Intercept
143.9351
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 6 hours ago · ID: stock-cost-vs-stock-dxcm-daily