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 1.26% per annum.
- VRTX price at the close of September 25, 2026 was $526.19 and was inside the primary price channel.
- The secondary trend is increasing.
- The growth rate of the secondary trend is 25.82% per annum.
- VRTX price at the close of September 25, 2026 was inside the secondary price channel.
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 VRTX 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: December 13, 2023
End date: August 7, 2026
a = 6.0609
b = 0.0000
s = 0.0728
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × 0.0000) – 1
= 1.26%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0728) – 1
= 33.80%
December 13, 2023 calculations
Top border of price channel:
Exp(Y557)
= Exp(a + b × X557 + 2 × s)
= Exp(a + b × 807 + 2 × s)
= Exp(6.0609 + 0.0000 × 807 + 2 × 0.0728)
= Exp(6.2341)
= $509.85
Bottom border of price channel:
Exp(Y557)
= Exp(a + b × X557 – 2 × s)
= Exp(a + b × 807 – 2 × s)
= Exp(6.0609 + 0.0000 × 807 – 2 × 0.0728)
= Exp(5.9429)
= $381.04
August 7, 2026 calculations
Top border of price channel:
Exp(Y1,220)
= Exp(a + b × X1,220 + 2 × s)
= Exp(a + b × 1,775 + 2 × s)
= Exp(6.0609 + 0.0000 × 1,775 + 2 × 0.0728)
= Exp(6.2673)
= $527.04
Bottom border of price channel:
Exp(Y1,220)
= Exp(a + b × X1,220 – 2 × s)
= Exp(a + b × 1,775 – 2 × s)
= Exp(6.0609 + 0.0000 × 1,775 – 2 × 0.0728)
= Exp(5.9761)
= $393.89
Description
- The primary trend is increasing.
- The growth rate of the primary trend is 1.26% per annum.
- VRTX price at the close of September 25, 2026 was $526.19 and was inside the primary price channel.
Secondary Trend
Start date: August 5, 2025
End date: September 25, 2026
a = 5.0931
b = 0.0006
s = 0.0524
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × 0.0006) – 1
= 25.82%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0524) – 1
= 23.32%
August 5, 2025 calculations
Top border of price channel:
Exp(Y967)
= Exp(a + b × X967 + 2 × s)
= Exp(a + b × 1,408 + 2 × s)
= Exp(5.0931 + 0.0006 × 1,408 + 2 × 0.0524)
= Exp(6.0840)
= $438.78
Bottom border of price channel:
Exp(Y967)
= Exp(a + b × X967 – 2 × s)
= Exp(a + b × 1,408 – 2 × s)
= Exp(5.0931 + 0.0006 × 1,408 – 2 × 0.0524)
= Exp(5.8744)
= $355.80
September 25, 2026 calculations
Top border of price channel:
Exp(Y1,254)
= Exp(a + b × X1,254 + 2 × s)
= Exp(a + b × 1,824 + 2 × s)
= Exp(5.0931 + 0.0006 × 1,824 + 2 × 0.0524)
= Exp(6.3458)
= $570.09
Bottom border of price channel:
Exp(Y1,254)
= Exp(a + b × X1,254 – 2 × s)
= Exp(a + b × 1,824 – 2 × s)
= Exp(5.0931 + 0.0006 × 1,824 – 2 × 0.0524)
= Exp(6.1362)
= $462.27
Description
- The secondary trend is increasing.
- The growth rate of the secondary trend is 25.82% per annum.
- VRTX price at the close of September 25, 2026 was inside the secondary price channel.