Stock Price Trends

Group 1 Automotive Inc (GPI)

Group 1 Automotive, Inc. is a leading automotive retailer headquartered in Houston, Texas, operating a diverse portfolio of dealerships across the United States, the UK, and Brazil. The company focuses on providing a comprehensive range of services, including new and used vehicle sales, automotive repair, and financing solutions, making it a significant player in the retail automotive sector. With a strong commitment to customer satisfaction and operational efficiency, Group 1 Automotive is well-positioned to capitalize on market trends while delivering sustainable growth and value to its investors.

Stock Price Trends

Stock price trends estimated using linear regression.

Key facts

  • The primary trend is decreasing.
  • The decline rate of the primary trend is 0.86% per annum.
  • GPI price at the close of December 26, 2025 was $407.56 and was inside the primary price channel.
  • The secondary trend is decreasing.
  • The decline rate of the secondary trend is 43.45% per annum.
  • GPI price at the close of December 26, 2025 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 GPI 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: November 6, 2024
End date: December 26, 2025

a = 6.0932

b = 0.0000

s = 0.0599

Annual growth rate:

Exp(365 × b) – 1
= Exp(365 × 0.0000) – 1
= -0.86%

Price channel spread:

Exp(4 × s) – 1
= Exp(4 × 0.0599) – 1
= 27.08%

November 6, 2024 calculations

Top border of price channel:

Exp(Y970)
= Exp(a + b × X970 + 2 × s)
= Exp(a + b × 1,408 + 2 × s)
= Exp(6.0932 + 0.0000 × 1,408 + 2 × 0.0599)
= Exp(6.1797)
= $482.84

Bottom border of price channel:

Exp(Y970)
= Exp(a + b × X970 – 2 × s)
= Exp(a + b × 1,408 – 2 × s)
= Exp(6.0932 + 0.0000 × 1,408 – 2 × 0.0599)
= Exp(5.9400)
= $379.94

December 26, 2025 calculations

Top border of price channel:

Exp(Y1,254)
= Exp(a + b × X1,254 + 2 × s)
= Exp(a + b × 1,823 + 2 × s)
= Exp(6.0932 + 0.0000 × 1,823 + 2 × 0.0599)
= Exp(6.1699)
= $478.12

Bottom border of price channel:

Exp(Y1,254)
= Exp(a + b × X1,254 – 2 × s)
= Exp(a + b × 1,823 – 2 × s)
= Exp(6.0932 + 0.0000 × 1,823 – 2 × 0.0599)
= Exp(5.9302)
= $376.22

Description

  • The primary trend is decreasing.
  • The decline rate of the primary trend is 0.86% per annum.
  • GPI price at the close of December 26, 2025 was $407.56 and was inside the primary price channel.

Secondary Trend

Start date: August 22, 2025
End date: December 26, 2025

a = 8.8027

b = -0.0016

s = 0.0394

Annual growth rate:

Exp(365 × b) – 1
= Exp(365 × -0.0016) – 1
= -43.45%

Price channel spread:

Exp(4 × s) – 1
= Exp(4 × 0.0394) – 1
= 17.07%

August 22, 2025 calculations

Top border of price channel:

Exp(Y1,167)
= Exp(a + b × X1,167 + 2 × s)
= Exp(a + b × 1,697 + 2 × s)
= Exp(8.8027 + -0.0016 × 1,697 + 2 × 0.0394)
= Exp(6.2310)
= $508.28

Bottom border of price channel:

Exp(Y1,167)
= Exp(a + b × X1,167 – 2 × s)
= Exp(a + b × 1,697 – 2 × s)
= Exp(8.8027 + -0.0016 × 1,697 – 2 × 0.0394)
= Exp(6.0734)
= $434.16

December 26, 2025 calculations

Top border of price channel:

Exp(Y1,254)
= Exp(a + b × X1,254 + 2 × s)
= Exp(a + b × 1,823 + 2 × s)
= Exp(8.8027 + -0.0016 × 1,823 + 2 × 0.0394)
= Exp(6.0342)
= $417.48

Bottom border of price channel:

Exp(Y1,254)
= Exp(a + b × X1,254 – 2 × s)
= Exp(a + b × 1,823 – 2 × s)
= Exp(8.8027 + -0.0016 × 1,823 – 2 × 0.0394)
= Exp(5.8766)
= $356.61

Description

  • The secondary trend is decreasing.
  • The decline rate of the secondary trend is 43.45% per annum.
  • GPI price at the close of December 26, 2025 was inside the secondary price channel.