Stock Price Trends
Stock price trends estimated using linear regression.
Summary
Key facts
- The primary trend is decreasing.
- The decline rate of the primary trend is 4.10% per annum.
- VRTX price at the close of July 16, 2026 was $486.03 and was inside the primary price channel.
- The secondary trend is increasing.
- The growth rate of the secondary trend is 21.07% per annum.
- VRTX price at the close of July 16, 2026 was inside the secondary price channel.
- The direction of the secondary trend is opposite to the direction of the primary trend. This indicates a possible reversal in the direction of the primary trend.
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: May 15, 2024
End date: June 23, 2026
a = 6.2775
b = -0.0001
s = 0.0648
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × -0.0001) – 1
= -4.10%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0648) – 1
= 29.58%
May 15, 2024 calculations
Top border of price channel:
Exp(Y711)
= Exp(a + b × X711 + 2 × s)
= Exp(a + b × 1,031 + 2 × s)
= Exp(6.2775 + -0.0001 × 1,031 + 2 × 0.0648)
= Exp(6.2889)
= $538.55
Bottom border of price channel:
Exp(Y711)
= Exp(a + b × X711 – 2 × s)
= Exp(a + b × 1,031 – 2 × s)
= Exp(6.2775 + -0.0001 × 1,031 – 2 × 0.0648)
= Exp(6.0298)
= $415.61
June 23, 2026 calculations
Top border of price channel:
Exp(Y1,237)
= Exp(a + b × X1,237 + 2 × s)
= Exp(a + b × 1,800 + 2 × s)
= Exp(6.2775 + -0.0001 × 1,800 + 2 × 0.0648)
= Exp(6.2007)
= $493.10
Bottom border of price channel:
Exp(Y1,237)
= Exp(a + b × X1,237 – 2 × s)
= Exp(a + b × 1,800 – 2 × s)
= Exp(6.2775 + -0.0001 × 1,800 – 2 × 0.0648)
= Exp(5.9416)
= $380.54
Description
- The primary trend is decreasing.
- The decline rate of the primary trend is 4.10% per annum.
- VRTX price at the close of July 16, 2026 was $486.03 and was inside the primary price channel.
Secondary Trend
Start date: August 5, 2025
End date: July 16, 2026
a = 5.2183
b = 0.0005
s = 0.0516
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × 0.0005) – 1
= 21.07%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0516) – 1
= 22.91%
August 5, 2025 calculations
Top border of price channel:
Exp(Y1,016)
= Exp(a + b × X1,016 + 2 × s)
= Exp(a + b × 1,478 + 2 × s)
= Exp(5.2183 + 0.0005 × 1,478 + 2 × 0.0516)
= Exp(6.0957)
= $443.96
Bottom border of price channel:
Exp(Y1,016)
= Exp(a + b × X1,016 – 2 × s)
= Exp(a + b × 1,478 – 2 × s)
= Exp(5.2183 + 0.0005 × 1,478 – 2 × 0.0516)
= Exp(5.8894)
= $361.20
July 16, 2026 calculations
Top border of price channel:
Exp(Y1,253)
= Exp(a + b × X1,253 + 2 × s)
= Exp(a + b × 1,823 + 2 × s)
= Exp(5.2183 + 0.0005 × 1,823 + 2 × 0.0516)
= Exp(6.2765)
= $531.91
Bottom border of price channel:
Exp(Y1,253)
= Exp(a + b × X1,253 – 2 × s)
= Exp(a + b × 1,823 – 2 × s)
= Exp(5.2183 + 0.0005 × 1,823 – 2 × 0.0516)
= Exp(6.0702)
= $432.76
Description
- The secondary trend is increasing.
- The growth rate of the secondary trend is 21.07% per annum.
- VRTX price at the close of July 16, 2026 was inside the secondary price channel.