Stock Price Trends

Group 1 Automotive Inc (GPI)

Group 1 Automotive, Inc., operates in the automotive retail industry. The company is headquartered in Houston, Texas.

Stock Price Trends

Stock price trends estimated using linear regression.

Key facts

  • The primary trend is increasing.
  • The growth rate of the primary trend is 8.03% per annum.
  • GPI price at the close of April 28, 2025 was $407.11 and was higher than the top border of the primary price channel by $150.09 (58.39%).
  • The secondary trend is increasing.
  • The growth rate of the secondary trend is 41.36% per annum.
  • GPI price at the close of April 28, 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: December 30, 2020
End date: January 25, 2023

a = 4.9952

b = 0.0002

s = 0.0840

Annual growth rate:

Exp(365 × b) – 1
= Exp(365 × 0.0002) – 1
= 8.03%

Price channel spread:

Exp(4 × s) – 1
= Exp(4 × 0.0840) – 1
= 39.93%

December 30, 2020 calculations

Top border of price channel:

Exp(Y170)
= Exp(a + b × X170 + 2 × s)
= Exp(a + b × 245 + 2 × s)
= Exp(4.9952 + 0.0002 × 245 + 2 × 0.0840)
= Exp(5.2150)
= $184.01

Bottom border of price channel:

Exp(Y170)
= Exp(a + b × X170 – 2 × s)
= Exp(a + b × 245 – 2 × s)
= Exp(4.9952 + 0.0002 × 245 – 2 × 0.0840)
= Exp(4.8790)
= $131.50

January 25, 2023 calculations

Top border of price channel:

Exp(Y690)
= Exp(a + b × X690 + 2 × s)
= Exp(a + b × 1,001 + 2 × s)
= Exp(4.9952 + 0.0002 × 1,001 + 2 × 0.0840)
= Exp(5.3749)
= $215.91

Bottom border of price channel:

Exp(Y690)
= Exp(a + b × X690 – 2 × s)
= Exp(a + b × 1,001 – 2 × s)
= Exp(4.9952 + 0.0002 × 1,001 – 2 × 0.0840)
= Exp(5.0389)
= $154.30

Description

  • The primary trend is increasing.
  • The growth rate of the primary trend is 8.03% per annum.
  • GPI price at the close of April 28, 2025 was $407.11 and was higher than the top border of the primary price channel by $150.09 (58.39%).

Secondary Trend

Start date: March 31, 2022
End date: April 28, 2025

a = 4.3552

b = 0.0009

s = 0.0800

Annual growth rate:

Exp(365 × b) – 1
= Exp(365 × 0.0009) – 1
= 41.36%

Price channel spread:

Exp(4 × s) – 1
= Exp(4 × 0.0800) – 1
= 37.69%

March 31, 2022 calculations

Top border of price channel:

Exp(Y485)
= Exp(a + b × X485 + 2 × s)
= Exp(a + b × 701 + 2 × s)
= Exp(4.3552 + 0.0009 × 701 + 2 × 0.0800)
= Exp(5.1798)
= $177.65

Bottom border of price channel:

Exp(Y485)
= Exp(a + b × X485 – 2 × s)
= Exp(a + b × 701 – 2 × s)
= Exp(4.3552 + 0.0009 × 701 – 2 × 0.0800)
= Exp(4.8600)
= $129.03

April 28, 2025 calculations

Top border of price channel:

Exp(Y1,255)
= Exp(a + b × X1,255 + 2 × s)
= Exp(a + b × 1,825 + 2 × s)
= Exp(4.3552 + 0.0009 × 1,825 + 2 × 0.0800)
= Exp(6.2457)
= $515.77

Bottom border of price channel:

Exp(Y1,255)
= Exp(a + b × X1,255 – 2 × s)
= Exp(a + b × 1,825 – 2 × s)
= Exp(4.3552 + 0.0009 × 1,825 – 2 × 0.0800)
= Exp(5.9258)
= $374.59

Description

  • The secondary trend is increasing.
  • The growth rate of the secondary trend is 41.36% per annum.
  • GPI price at the close of April 28, 2025 was inside the secondary price channel.