Stock Price Trends

CarMax Inc (KMX)

CarMax is a used vehicle retailer based in the United States. It operates two business segments: CarMax Sales Operations and CarMax Auto Finance.

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 8.18% per annum.
  • KMX price at the close of April 28, 2025 was $65.11 and was lower than the bottom border of the primary price channel by $3.29 (4.81%). This indicates a possible reversal in the primary trend direction.
  • The secondary trend is decreasing.
  • The decline rate of the secondary trend is 70.21% per annum.
  • KMX price at the close of April 28, 2025 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 KMX 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: September 29, 2022
End date: April 9, 2025

a = 4.0076

b = 0.0002

s = 0.0877

Annual growth rate:

Exp(365 × b) – 1
= Exp(365 × 0.0002) – 1
= 8.18%

Price channel spread:

Exp(4 × s) – 1
= Exp(4 × 0.0877) – 1
= 42.04%

September 29, 2022 calculations

Top border of price channel:

Exp(Y610)
= Exp(a + b × X610 + 2 × s)
= Exp(a + b × 883 + 2 × s)
= Exp(4.0076 + 0.0002 × 883 + 2 × 0.0877)
= Exp(4.3733)
= $79.31

Bottom border of price channel:

Exp(Y610)
= Exp(a + b × X610 – 2 × s)
= Exp(a + b × 883 – 2 × s)
= Exp(4.0076 + 0.0002 × 883 – 2 × 0.0877)
= Exp(4.0224)
= $55.83

April 9, 2025 calculations

Top border of price channel:

Exp(Y1,243)
= Exp(a + b × X1,243 + 2 × s)
= Exp(a + b × 1,806 + 2 × s)
= Exp(4.0076 + 0.0002 × 1,806 + 2 × 0.0877)
= Exp(4.5722)
= $96.76

Bottom border of price channel:

Exp(Y1,243)
= Exp(a + b × X1,243 – 2 × s)
= Exp(a + b × 1,806 – 2 × s)
= Exp(4.0076 + 0.0002 × 1,806 – 2 × 0.0877)
= Exp(4.2212)
= $68.12

Description

  • The primary trend is increasing.
  • The growth rate of the primary trend is 8.18% per annum.
  • KMX price at the close of April 28, 2025 was $65.11 and was lower than the bottom border of the primary price channel by $3.29 (4.81%). This indicates a possible reversal in the primary trend direction.

Secondary Trend

Start date: January 27, 2025
End date: April 28, 2025

a = 10.2422

b = -0.0033

s = 0.0510

Annual growth rate:

Exp(365 × b) – 1
= Exp(365 × -0.0033) – 1
= -70.21%

Price channel spread:

Exp(4 × s) – 1
= Exp(4 × 0.0510) – 1
= 22.63%

January 27, 2025 calculations

Top border of price channel:

Exp(Y1,192)
= Exp(a + b × X1,192 + 2 × s)
= Exp(a + b × 1,734 + 2 × s)
= Exp(10.2422 + -0.0033 × 1,734 + 2 × 0.0510)
= Exp(4.5907)
= $98.56

Bottom border of price channel:

Exp(Y1,192)
= Exp(a + b × X1,192 – 2 × s)
= Exp(a + b × 1,734 – 2 × s)
= Exp(10.2422 + -0.0033 × 1,734 – 2 × 0.0510)
= Exp(4.3866)
= $80.37

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(10.2422 + -0.0033 × 1,825 + 2 × 0.0510)
= Exp(4.2887)
= $72.87

Bottom border of price channel:

Exp(Y1,255)
= Exp(a + b × X1,255 – 2 × s)
= Exp(a + b × 1,825 – 2 × s)
= Exp(10.2422 + -0.0033 × 1,825 – 2 × 0.0510)
= Exp(4.0847)
= $59.42

Description

  • The secondary trend is decreasing.
  • The decline rate of the secondary trend is 70.21% per annum.
  • KMX price at the close of April 28, 2025 was inside the secondary price channel.