SeriesMagCorrOverlapThrough
These move together about 55% of the time
Strong positive
Strong enough to use as a signal — read the stability and regime notes below before relying on it.
American Tower owns and operates about 150,000 wireless towers throughout the US, Asia, Latin America, Europe, and Africa. It also owns and/or operates 30 data centers in 11 US markets after acquiring CoreSite. The company's customer base in the tower business is very concentrated, with most revenue in each market generated by the top three or four mobile carriers. The company operates more than 40,000 towers in the US, which accounted for about half of total revenue in 2025. Outside the US, American Tower operates about 47,000 towers in Latin America (dominated by Brazil), 33,000 towers in Europe, and 28,000 towers in Africa. American Tower operates as a REIT.
Market cap 81.8B · 4,866 employees
Nio is a leading electric vehicle maker, targeting the premium segment. Founded in November 2014, Nio designs, develops, jointly manufactures, and sells premium smart electric vehicles. The company differentiates itself through continuous technological breakthroughs and innovations such as battery swapping and autonomous driving technologies. Nio launched its first model, its ES8 seven-seater electric SUV, in December 2017, and began deliveries in June 2018. Its current model portfolio includes midsize to large sedans and SUVs. It sold around 326,000 EVs in 2025, accounting for about 2% of the China passenger new energy vehicle market.
What to Watch
Unusual right now
Recent correlation (-57%) is 3.0σ from the long-run average of +82% — pair is behaving differently than usual.
Holds across regimes
Correlation is similar when markets rise (+18%) and fall (+23%) — 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
+82%
No shift — both series at their actual dates.
1,255 overlapping points at this shift
Time series with NIO Inc. American depositary shares, each representing one Class A ordinary share 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
+82%
Pearson correlation
95% CI
+80% → +84%
Likely range
R²
66.9%
Variance explained
Trend agreement
54.9%
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 15.6B · 35,032 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
+18%
68 periods · Return correlation when both series rose
Both Falling
+23%
90 periods · Return correlation when both series fell
Diverging
-46%
91 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
American Tower Corporation
AMT
Market cap 81.8B · 4,866 employees
Stock · 1,255 raw → 1,255 prepared
Series B
NIO Inc. American depositary shares, each representing one Class A ordinary share
NIO
Market cap 15.6B · 35,032 employees
Stock · 1,255 raw → 1,255 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
45
Estimated crossover points between normalized spreads.
Slope
0.2883
Linear regression slope.
Intercept
-49.1763
Linear regression intercept.
Saved 1 hour ago · ID: stock-amt_stock-nio_5y
NIO
NIO Inc. American depositary shares, each representing one Class A ordinary share
Strongest positive