Correlation Analysis
Aflac Inc. vs Costco Wholesale Corp
AFL vs COST
+0.954
Very strong positive
When one moves up, the other tends to follow.

Aflac Inc.
↗AFL
Aflac Inc offers supplemental health insurance and life insurance in the United States and Japan. In addition to its cancer policies, the company has broadened its product offerings to include accident, dental and vision, disability, and long-term-care insurance. It markets its products through independent distributors, selling the majority of its policies directly to consumers at their places of work, and also reaches out to its customers outside of their worksite through digital mediums. The company has two reportable business segments: Aflac Japan, which generates the maximum revenue, and Aflac U.S.
Market cap 56.8B · 12,716 employees
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
Time Series
Relative Performance
Who Moves First
in sync
AFL and COST tend to move at the same time.
After testing 13 timing shifts, the strongest relationship was +0.954 (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
-0.131
17 periods · Return correlation when both series rose
Both Falling
-0.083
5 periods · Return correlation when both series fell
Diverging
-0.809
13 periods · Return correlation when series moved apart
R-Squared
91.0%
Share of variance in one series explained by the other.
Trend Agreement
59.4%
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: [0.948, 0.958]
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

Aflac Inc.
AFL
Market cap 56.8B · 12,716 employees
Stock · 1,254 raw → 1,254 prepared
Series B
Costco Wholesale Corp
COST
Market cap 451.9B
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
9.6458
Linear regression slope.
Intercept
-99.9804
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 7 hours ago · ID: stock-afl-vs-stock-cost-daily