Correlation Analysis
Costco Wholesale Corp vs eBay Inc
COST vs EBAY
+0.584
Moderate 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
eBay Inc
↗EBAY
EBay operates one of the largest e-commerce marketplaces in the world, with $79.6 billion in 2025 gross merchandise volume, rendering the firm a top 10 global e-commerce company. It generates sales from listing fees, advertising, revenue-sharing arrangements with service providers, and managed payments, with its platform connecting about 135 million buyers and roughly 20 million sellers across almost 190 global markets at the end of 2025. EBay generates just north of 50% of its GMV in international markets, with a large presence in the UK, Germany, and Australia.
Market cap 43.8B · 12,300 employees
Time Series
Relative Performance
Who Moves First
COST leads EBAY by 6 days
COST tends to move before EBAY.
After testing 13 timing shifts, the strongest relationship was +0.588 (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
-0.233
15 periods · Return correlation when both series rose
Both Falling
+0.672
7 periods · Return correlation when both series fell
Diverging
-0.575
13 periods · Return correlation when series moved apart
R-Squared
34.1%
Share of variance in one series explained by the other.
Trend Agreement
62.4%
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: [0.546, 0.619]
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
eBay Inc
EBAY
Market cap 43.8B · 12,300 employees
Stock · 1,254 raw → 1,254 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
5
Estimated crossover points between normalized spreads.
Slope
0.0443
Linear regression slope.
Intercept
29.7429
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 5 hours ago · ID: stock-cost-vs-stock-ebay-daily