Correlation Analysis
Apple Inc. vs Merck & Co., Inc.
AAPL vs MRK
+0.253
Light positive
When one moves up, the other tends to follow.
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
Merck & Co., Inc.
↗MRK
Merck makes pharmaceutical products to treat several conditions in a number of therapeutic areas, including cardiometabolic disease, cancer, and infections. Within cancer, the firm's immuno-oncology platform, led by Keytruda, is a major contributor to overall sales. The company also has a substantial vaccine business aimed at preventing pediatric diseases, as well as Gardasil for human papillomavirus. Additionally, Merck sells animal health-related drugs. From a geographical perspective, 47% of the company's sales are generated from US human health (pharmaceuticals and vaccines).
Market cap 298.8B
Time Series
Rebased to 100
Who Moves First
in sync
AAPL and MRK tend to move at the same time.
Best correlation after shifting: +0.253 (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
-0.630
8 periods · Return correlation when both series rose
Both Falling
-0.410
5 periods · Return correlation when both series fell
Diverging
-0.624
22 periods · Return correlation when series moved apart
R-Squared
6.4%
Share of variance in one series explained by the other.
Trend Agreement
55.7%
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: [0.200, 0.304]
Scatter
XY Regression
Pipeline
Data quality details
Pipeline
Data quality details
Pipeline Summary
1,254 paired observations 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
Apple Inc.
AAPL
Market cap 3.8T
Stock · 1,254 raw → 1,254 prepared
Series B
Merck & Co., Inc.
MRK
Market cap 298.8B
Stock · 1,254 raw → 1,254 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
21
Estimated crossover points between normalized spreads.
Slope
0.1035
Linear regression slope.
Intercept
78.7347
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 3 hours ago · ID: stock-aapl-vs-stock-mrk-daily-20260408-qplo29