Stock Price Trends
Stock price trends estimated using linear regression.
Summary
Key facts
- The primary trend is increasing.
- The growth rate of the primary trend is 7.79% per annum.
- FCX price at the close of September 18, 2026 was $71.54 and was inside the primary price channel.
- The secondary trend is increasing.
- The growth rate of the secondary trend is 338.76% per annum.
- FCX price at the close of September 18, 2026 was lower than the bottom border of the secondary price channel by $1.82 (2.49%). This indicates a possible reversal in the secondary trend direction.
Linear Regression Model
Model equation:
Yi = α + β × Xi + εi
Top border of price channel:
Exp(Yi) = Exp(a + b × Xi + 2 × s)
Bottom border of price channel:
Exp(Yi) = Exp(a + b × Xi – 2 × s)
where:
i - observation number
Yi - natural logarithm of FCX price
Xi - time index, 1 day interval
σ - standard deviation of εi
a - estimator of α
b - estimator of β
s - estimator of σ
Exp() - calculates the exponent of e
Primary Trend
Start date: January 9, 2026
End date: August 4, 2026
a = 4.0668
b = 0.0002
s = 0.0647
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × 0.0002) – 1
= 7.79%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0647) – 1
= 29.54%
January 9, 2026 calculations
Top border of price channel:
Exp(Y143)
= Exp(a + b × X143 + 2 × s)
= Exp(a + b × 207 + 2 × s)
= Exp(4.0668 + 0.0002 × 207 + 2 × 0.0647)
= Exp(4.2388)
= $69.33
Bottom border of price channel:
Exp(Y143)
= Exp(a + b × X143 – 2 × s)
= Exp(a + b × 207 – 2 × s)
= Exp(4.0668 + 0.0002 × 207 – 2 × 0.0647)
= Exp(3.9800)
= $53.52
August 4, 2026 calculations
Top border of price channel:
Exp(Y284)
= Exp(a + b × X284 + 2 × s)
= Exp(a + b × 414 + 2 × s)
= Exp(4.0668 + 0.0002 × 414 + 2 × 0.0647)
= Exp(4.2814)
= $72.34
Bottom border of price channel:
Exp(Y284)
= Exp(a + b × X284 – 2 × s)
= Exp(a + b × 414 – 2 × s)
= Exp(4.0668 + 0.0002 × 414 – 2 × 0.0647)
= Exp(4.0226)
= $55.84
Description
- The primary trend is increasing.
- The growth rate of the primary trend is 7.79% per annum.
- FCX price at the close of September 18, 2026 was $71.54 and was inside the primary price channel.
Secondary Trend
Start date: June 29, 2026
End date: September 9, 2026
a = 2.5230
b = 0.0041
s = 0.0436
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × 0.0041) – 1
= 338.76%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0436) – 1
= 19.04%
June 29, 2026 calculations
Top border of price channel:
Exp(Y259)
= Exp(a + b × X259 + 2 × s)
= Exp(a + b × 378 + 2 × s)
= Exp(2.5230 + 0.0041 × 378 + 2 × 0.0436)
= Exp(4.1416)
= $62.90
Bottom border of price channel:
Exp(Y259)
= Exp(a + b × X259 – 2 × s)
= Exp(a + b × 378 – 2 × s)
= Exp(2.5230 + 0.0041 × 378 – 2 × 0.0436)
= Exp(3.9673)
= $52.84
September 9, 2026 calculations
Top border of price channel:
Exp(Y309)
= Exp(a + b × X309 + 2 × s)
= Exp(a + b × 450 + 2 × s)
= Exp(2.5230 + 0.0041 × 450 + 2 × 0.0436)
= Exp(4.4333)
= $84.21
Bottom border of price channel:
Exp(Y309)
= Exp(a + b × X309 – 2 × s)
= Exp(a + b × 450 – 2 × s)
= Exp(2.5230 + 0.0041 × 450 – 2 × 0.0436)
= Exp(4.2590)
= $70.74
Description
- The secondary trend is increasing.
- The growth rate of the secondary trend is 338.76% per annum.
- FCX price at the close of September 18, 2026 was lower than the bottom border of the secondary price channel by $1.82 (2.49%). This indicates a possible reversal in the secondary trend direction.