SeriesMagCorrOverlapThrough
These move opposite each other about 55% of the time
Strong inverse
Strong enough to use as a signal — read the stability and regime notes below before relying on it.
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% f
Market cap 442.8B · 341,000 employees
Plug Power Inc is building an end-to-end green hydrogen ecosystem, from production, storage, and delivery to energy generation. The company plans to build and operate green hydrogen highways across North America and Europe. Plug will deliver its green hydrogen solutions directly to its customers and through joint venture partners into multiple end markets, including material handling, e-mobility, power generation, and industrial applications.
What to Watch
Holds across regimes
Correlation is similar when markets rise (+3%) and fall (+0%) — reliable in both directions.
Regime-dependent
The correlation has flipped sign across time windows — not reliable as a standalone signal.
Time Series
Time-Shifted Correlation
See how correlation changes when one series is offset in time. A taller bar at a non-zero shift means the two move together better when one leads the other — that's a potential lead/lag signal.
Correlation by shift
Click a bar to inspect. Range: -6 to 6 days.
Selected shift
No shift
Correlation at this shift
-78%
No shift — both series at their actual dates.
1,255 overlapping points at this shift
Time series with Plug Power Inc. at original dates
Indexed to 100 at start
Deep Dive
Stability
How the correlation evolves over time. A stable line means the relationship is reliable; large swings signal regime-dependent behavior.
Corr
-78%
Pearson correlation
95% CI
-80% → -75%
Likely range
R²
60.2%
Variance explained
Trend agreement
55.1%
Same-direction moves
Significance
p < 0.001
Statistical confidence
Data points
1,255
Deep
Pipeline
Pipeline Summary
1,255 paired data points survived the daily window.
Raw input
1,255
1,255
Normalized
1,255
1,255
Prepared
1,255
1,255
Aligned
1,255
1,255
Invalid removed
Explore
The strongest positive and inverse pairs we’ve saved for each side of this comparison — good jumping-off points if this result raised a question.
Market cap 4.3B · 2,582 employees
Do They Crash Together?
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
+3%
71 periods · Return correlation when both series rose
Both Falling
+0%
76 periods · Return correlation when both series fell
Diverging
-33%
102 periods · Return correlation when series moved apart
Scatter
0
A: 0 / B: 0
Duplicates removed
0
A: 0 / B: 0
Alignment drops
0
A: 0 / B: 0
Series A
Costco Wholesale Corp
COST
Market cap 442.8B · 341,000 employees
Stock · 1,255 raw → 1,255 prepared
Series B
Plug Power Inc.
PLUG
Market cap 4.3B · 2,582 employees
Stock · 1,255 raw → 1,255 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
3
Estimated crossover points between normalized spreads.
Slope
-0.0393
Linear regression slope.
Intercept
38.3715
Linear regression intercept.
Saved 2 hours ago · ID: stock-cost_stock-plug_5y
PLUG
Plug Power Inc.
Strongest positive