Correlation Analysis
Apple Inc. vs Sandisk Corporation Common Stock
AAPL vs SNDK
+0.629
Moderate 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
Sandisk Corporation Common Stock
↗SNDK
Sandisk is one of the five largest suppliers of NAND flash memory semiconductors globally. Sandisk is vertically integrated, producing substantially all of its flash chips at manufacturing sites across Japan via a joint-venture framework with Kioxia. Sandisk then repackages most of its chips into SSDs for consumer electronics, external storage, or cloud storage. Sandisk was formerly a piece of Western Digital for nine years (after being acquired in 2016) and was spun off as an independent company in 2025.
Market cap 107B · 11,000 employees
Time Series
Relative Performance
Who Moves First
AAPL leads SNDK by 6 days
AAPL tends to move before SNDK.
After testing 13 timing shifts, the strongest relationship was +0.654 (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
+0.203
13 periods · Return correlation when both series rose
Both Falling
N/A
4 periods · Return correlation when both series fell
Diverging
-0.480
18 periods · Return correlation when series moved apart
R-Squared
39.6%
Share of variance in one series explained by the other.
Trend Agreement
62.1%
How often both series moved in the same direction period-to-period.
Overlap Quality
281
Robust shared window — 281 usable pairs.
Significance
p < 0.001
95% CI: [0.553, 0.695]
Scatter
XY Regression
Pipeline
Data quality details
Pipeline
Data quality details
Pipeline Summary
281 paired data points survived the daily window.
Raw input
1,254
281
Normalized
1,254
281
Prepared
1,254
281
Aligned
281
281
Invalid removed
0
A: 0 / B: 0
Duplicates removed
0
A: 0 / B: 0
Alignment drops
973
A: 973 / B: 0
Series A
Apple Inc.
AAPL
Market cap 3.8T
Stock · 1,254 raw → 1,254 prepared
Series B
Sandisk Corporation Common Stock
SNDK
Market cap 107B · 11,000 employees
Stock · 281 raw → 281 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
5
Estimated crossover points between normalized spreads.
Slope
4.9957
Linear regression slope.
Intercept
-985.4739
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
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