Correlation Analysis
Apple Inc. vs Biogen Inc. Common Stock
AAPL vs BIIB
-0.693
Strong inverse
When one moves up, the other tends to move down.
Apple Inc.
↗AAPL
Apple is among the largest companies in the world, with a broad portfolio of hardware and software products targeted at consumers and businesses. Apple's iPhone makes up a majority of the firm sales, and Apple's other products like Mac, iPad, and Watch are designed around the iPhone as the focal point of an expansive software ecosystem. Apple has progressively worked to add new applications, like streaming video, subscription bundles, and augmented reality. The firm designs its own software and semiconductors while working with subcontractors like Foxconn and TSMC to build its products and chips. Slightly less than half of Apple's sales come directly through its flagship stores, with a majority of sales coming indirectly through partnerships and distribution.
Market cap 3.8T
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
Time Series
Rebased to 100
Who Moves First
AAPL leads BIIB by 6 days
AAPL tends to move before BIIB.
Best correlation after shifting: -0.703 (13 shifts scanned)
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
-0.052
12 periods · Return correlation when both series rose
Both Falling
-0.215
12 periods · Return correlation when both series fell
Diverging
-0.566
11 periods · Return correlation when series moved apart
R-Squared
48.0%
Share of variance in one series explained by the other.
Trend Agreement
60.3%
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: [-0.720, -0.663]
Scatter
XY Regression
Pipeline
Data quality details
Pipeline
Data quality details
Pipeline Summary
1,253 paired observations survived the daily window.
Raw input
1,254
1,253
Normalized
1,254
1,253
Prepared
1,254
1,253
Aligned
1,253
1,253
Invalid removed
0
A: 0 / B: 0
Duplicates removed
0
A: 0 / B: 0
Alignment drops
1
A: 1 / B: 0
Series A
Apple Inc.
AAPL
Market cap 3.8T
Stock · 1,254 raw → 1,254 prepared
Series B
Biogen Inc. Common Stock
BIIB
Market cap 25.3B · 7,500 employees
Stock · 1,253 raw → 1,253 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
15
Estimated crossover points between normalized spreads.
Slope
-1.0132
Linear regression slope.
Intercept
414.2319
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 3 hours ago · ID: stock-aapl-vs-stock-biib-daily-20260408-i0ou55