Correlation Analysis
Biogen Inc. Common Stock vs Costco Wholesale Corp
BIIB vs COST
-0.832
Strong inverse
When one moves up, the other tends to move down.
Biogen Inc. Common Stock
↗BIIB
Biogen is an established biopharmaceutical company focused on treatments for neurodegenerative and rare diseases. Its declining multiple sclerosis franchise is its largest revenue generator and contributed 40% of total revenue in 2025. Biogen also generates significant revenue from its CD20 collaboration agreements with Roche (19% of total in 2025), which includes oncology drugs Rituxan and Gazyva and multiple sclerosis drug Ocrevus. Biogen's newer franchises include Spinraza (spinal muscular atrophy, with partner Ionis), Leqembi (Alzheimer's disease, collabroation revenue from its partner Eisai), Skyclarys (Friedreich's ataxia, Reata), Zurzuvae (postpartum depression, Sage), and Qalsody (amyotrophic lateral sclerosis, Ionis).
Market cap 25.3B · 7,500 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
COST leads BIIB by 6 days
COST tends to move before BIIB.
After testing 13 timing shifts, the strongest relationship was -0.839 (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
-0.001
11 periods · Return correlation when both series rose
Both Falling
-0.230
8 periods · Return correlation when both series fell
Diverging
-0.606
16 periods · Return correlation when series moved apart
R-Squared
69.2%
Share of variance in one series explained by the other.
Trend Agreement
57.2%
How often both series moved in the same direction period-to-period.
Overlap Quality
1,253
Deep shared window — 1,253 usable pairs.
Significance
p < 0.001
95% CI: [-0.848, -0.814]
Scatter
XY Regression
Pipeline
Data quality details
Pipeline
Data quality details
Pipeline Summary
1,253 paired data points survived the daily window.
Raw input
1,253
1,254
Normalized
1,253
1,254
Prepared
1,253
1,254
Aligned
1,253
1,253
Invalid removed
0
A: 0 / B: 0
Duplicates removed
0
A: 0 / B: 0
Alignment drops
1
A: 0 / B: 1
Series A
Biogen Inc. Common Stock
BIIB
Market cap 25.3B · 7,500 employees
Stock · 1,253 raw → 1,253 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
1
Estimated crossover points between normalized spreads.
Slope
-2.9774
Linear regression slope.
Intercept
1347.3339
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
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