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 1.23% per annum.
- VRTX price at the close of October 23, 2026 was $523.93 and was inside the primary price channel.
- The secondary trend is increasing.
- The growth rate of the secondary trend is 25.25% per annum.
- VRTX price at the close of October 23, 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 6, 2026
a = 6.0627
b = 0.0000
s = 0.0728
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × 0.0000) – 1
= 1.23%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0728) – 1
= 33.79%
December 13, 2023 calculations
Top border of price channel:
Exp(Y537)
= Exp(a + b × X537 + 2 × s)
= Exp(a + b × 779 + 2 × s)
= Exp(6.0627 + 0.0000 × 779 + 2 × 0.0728)
= Exp(6.2343)
= $509.96
Bottom border of price channel:
Exp(Y537)
= Exp(a + b × X537 – 2 × s)
= Exp(a + b × 779 – 2 × s)
= Exp(6.0627 + 0.0000 × 779 – 2 × 0.0728)
= Exp(5.9432)
= $381.16
August 6, 2026 calculations
Top border of price channel:
Exp(Y1,199)
= Exp(a + b × X1,199 + 2 × s)
= Exp(a + b × 1,746 + 2 × s)
= Exp(6.0627 + 0.0000 × 1,746 + 2 × 0.0728)
= Exp(6.2667)
= $526.73
Bottom border of price channel:
Exp(Y1,199)
= Exp(a + b × X1,199 – 2 × s)
= Exp(a + b × 1,746 – 2 × s)
= Exp(6.0627 + 0.0000 × 1,746 – 2 × 0.0728)
= Exp(5.9756)
= $393.70
Description
- The primary trend is increasing.
- The growth rate of the primary trend is 1.23% per annum.
- VRTX price at the close of October 23, 2026 was $523.93 and was inside the primary price channel.
Secondary Trend
Start date: August 5, 2025
End date: October 23, 2026
a = 5.1298
b = 0.0006
s = 0.0512
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × 0.0006) – 1
= 25.25%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0512) – 1
= 22.71%
August 5, 2025 calculations
Top border of price channel:
Exp(Y947)
= Exp(a + b × X947 + 2 × s)
= Exp(a + b × 1,380 + 2 × s)
= Exp(5.1298 + 0.0006 × 1,380 + 2 × 0.0512)
= Exp(6.0833)
= $438.47
Bottom border of price channel:
Exp(Y947)
= Exp(a + b × X947 – 2 × s)
= Exp(a + b × 1,380 – 2 × s)
= Exp(5.1298 + 0.0006 × 1,380 – 2 × 0.0512)
= Exp(5.8787)
= $357.33
October 23, 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(5.1298 + 0.0006 × 1,824 + 2 × 0.0512)
= Exp(6.3571)
= $576.59
Bottom border of price channel:
Exp(Y1,254)
= Exp(a + b × X1,254 – 2 × s)
= Exp(a + b × 1,824 – 2 × s)
= Exp(5.1298 + 0.0006 × 1,824 – 2 × 0.0512)
= Exp(6.1525)
= $469.90
Description
- The secondary trend is increasing.
- The growth rate of the secondary trend is 25.25% per annum.
- VRTX price at the close of October 23, 2026 was inside the secondary price channel.