Correlation Analysis
Costco Wholesale Corp vs PHILLIPS 66
COST vs PSX
+0.739
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
PHILLIPS 66
↗PSX
Phillips 66 is an independent refiner that owns or holds interest in 10 refineries with a total crude throughput capacity of 2.0 million barrels per day, or mmb/d, at the end of 2025. The midstream segment comprises extensive transportation and NGL processing assets. It includes 70,000 miles of crude oil, refined petroleum product, NGL and natural gas pipeline systems, and a comprehensive set of refined petroleum product, NGL and crude oil terminals, gathering and processing plants and fractionation facilities and various other storage and loading facilities. Its CPChem chemical joint venture operates facilities primarily in the United States and the Middle East and produces olefins and polyolefins.
Market cap 71.1B · 12,600 employees
Time Series
Relative Performance
Who Moves First
in sync
COST and PSX tend to move at the same time.
After testing 13 timing shifts, the strongest relationship was +0.739 (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
+0.612
13 periods · Return correlation when both series rose
Both Falling
+0.860
6 periods · Return correlation when both series fell
Diverging
-0.790
16 periods · Return correlation when series moved apart
R-Squared
54.6%
Share of variance in one series explained by the other.
Trend Agreement
51.2%
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: [0.713, 0.763]
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
PHILLIPS 66
PSX
Market cap 71.1B · 12,600 employees
Stock · 1,254 raw → 1,254 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
9
Estimated crossover points between normalized spreads.
Slope
0.0890
Linear regression slope.
Intercept
51.3413
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 6 hours ago · ID: stock-cost-vs-stock-psx-daily