Stock Price Trends

Arthur J Gallagher & Co (AJG)

Arthur J. Gallagher & Co. (AJG) is an American global insurance brokerage and risk management services firm headquartered in Rolling Meadows, Illinois.

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 7.93% per annum.
  • AJG price at the close of July 11, 2025 was $311.54 and was inside the primary price channel.
  • The secondary trend is decreasing.
  • The decline rate of the secondary trend is 46.18% per annum.
  • AJG price at the close of July 11, 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 AJG 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: February 18, 2025
End date: July 11, 2025

a = 6.1906

b = -0.0002

s = 0.0284

Annual growth rate:

Exp(365 × b) – 1
= Exp(365 × -0.0002) – 1
= -7.93%

Price channel spread:

Exp(4 × s) – 1
= Exp(4 × 0.0284) – 1
= 12.05%

February 18, 2025 calculations

Top border of price channel:

Exp(Y1,155)
= Exp(a + b × X1,155 + 2 × s)
= Exp(a + b × 1,680 + 2 × s)
= Exp(6.1906 + -0.0002 × 1,680 + 2 × 0.0284)
= Exp(5.8672)
= $353.28

Bottom border of price channel:

Exp(Y1,155)
= Exp(a + b × X1,155 – 2 × s)
= Exp(a + b × 1,680 – 2 × s)
= Exp(6.1906 + -0.0002 × 1,680 – 2 × 0.0284)
= Exp(5.7535)
= $315.29

July 11, 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(6.1906 + -0.0002 × 1,823 + 2 × 0.0284)
= Exp(5.8349)
= $342.02

Bottom border of price channel:

Exp(Y1,254)
= Exp(a + b × X1,254 – 2 × s)
= Exp(a + b × 1,823 – 2 × s)
= Exp(6.1906 + -0.0002 × 1,823 – 2 × 0.0284)
= Exp(5.7211)
= $305.25

Description

  • The primary trend is decreasing.
  • The decline rate of the primary trend is 7.93% per annum.
  • AJG price at the close of July 11, 2025 was $311.54 and was inside the primary price channel.

Secondary Trend

Start date: May 15, 2025
End date: July 11, 2025

a = 8.8335

b = -0.0017

s = 0.0204

Annual growth rate:

Exp(365 × b) – 1
= Exp(365 × -0.0017) – 1
= -46.18%

Price channel spread:

Exp(4 × s) – 1
= Exp(4 × 0.0204) – 1
= 8.51%

May 15, 2025 calculations

Top border of price channel:

Exp(Y1,216)
= Exp(a + b × X1,216 + 2 × s)
= Exp(a + b × 1,766 + 2 × s)
= Exp(8.8335 + -0.0017 × 1,766 + 2 × 0.0204)
= Exp(5.8768)
= $356.68

Bottom border of price channel:

Exp(Y1,216)
= Exp(a + b × X1,216 – 2 × s)
= Exp(a + b × 1,766 – 2 × s)
= Exp(8.8335 + -0.0017 × 1,766 – 2 × 0.0204)
= Exp(5.7952)
= $328.71

July 11, 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(8.8335 + -0.0017 × 1,823 + 2 × 0.0204)
= Exp(5.7801)
= $323.79

Bottom border of price channel:

Exp(Y1,254)
= Exp(a + b × X1,254 – 2 × s)
= Exp(a + b × 1,823 – 2 × s)
= Exp(8.8335 + -0.0017 × 1,823 – 2 × 0.0204)
= Exp(5.6984)
= $298.40

Description

  • The secondary trend is decreasing.
  • The decline rate of the secondary trend is 46.18% per annum.
  • AJG price at the close of July 11, 2025 was inside the secondary price channel.