Stock Price Trends
Stock price trends estimated using linear regression.
Summary
Key facts
- The primary trend is increasing.
- The growth rate of the primary trend is 251.44% per annum.
- COST price at the close of October 30, 2026 was $1,012.28 and was inside the primary price channel.
- The secondary trend is increasing.
- The growth rate of the secondary trend is 13.71% per annum.
- COST price at the close of October 30, 2026 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 COST 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 16, 2026
End date: October 26, 2026
a = 5.5750
b = 0.0034
s = 0.0104
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × 0.0034) – 1
= 251.44%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0104) – 1
= 4.25%
September 16, 2026 calculations
Top border of price channel:
Exp(Y240)
= Exp(a + b × X240 + 2 × s)
= Exp(a + b × 350 + 2 × s)
= Exp(5.5750 + 0.0034 × 350 + 2 × 0.0104)
= Exp(6.8011)
= $898.79
Bottom border of price channel:
Exp(Y240)
= Exp(a + b × X240 – 2 × s)
= Exp(a + b × 350 – 2 × s)
= Exp(5.5750 + 0.0034 × 350 – 2 × 0.0104)
= Exp(6.7594)
= $862.15
October 26, 2026 calculations
Top border of price channel:
Exp(Y268)
= Exp(a + b × X268 + 2 × s)
= Exp(a + b × 390 + 2 × s)
= Exp(5.5750 + 0.0034 × 390 + 2 × 0.0104)
= Exp(6.9388)
= $1,031.53
Bottom border of price channel:
Exp(Y268)
= Exp(a + b × X268 – 2 × s)
= Exp(a + b × 390 – 2 × s)
= Exp(5.5750 + 0.0034 × 390 – 2 × 0.0104)
= Exp(6.8972)
= $989.47
Description
- The primary trend is increasing.
- The growth rate of the primary trend is 251.44% per annum.
- COST price at the close of October 30, 2026 was $1,012.28 and was inside the primary price channel.
Secondary Trend
Start date: October 16, 2026
End date: October 30, 2026
a = 6.7688
b = 0.0004
s = 0.0109
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × 0.0004) – 1
= 13.71%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0109) – 1
= 4.45%
October 16, 2026 calculations
Top border of price channel:
Exp(Y262)
= Exp(a + b × X262 + 2 × s)
= Exp(a + b × 380 + 2 × s)
= Exp(6.7688 + 0.0004 × 380 + 2 × 0.0109)
= Exp(6.9243)
= $1,016.67
Bottom border of price channel:
Exp(Y262)
= Exp(a + b × X262 – 2 × s)
= Exp(a + b × 380 – 2 × s)
= Exp(6.7688 + 0.0004 × 380 – 2 × 0.0109)
= Exp(6.8808)
= $973.38
October 30, 2026 calculations
Top border of price channel:
Exp(Y272)
= Exp(a + b × X272 + 2 × s)
= Exp(a + b × 394 + 2 × s)
= Exp(6.7688 + 0.0004 × 394 + 2 × 0.0109)
= Exp(6.9292)
= $1,021.69
Bottom border of price channel:
Exp(Y272)
= Exp(a + b × X272 – 2 × s)
= Exp(a + b × 394 – 2 × s)
= Exp(6.7688 + 0.0004 × 394 – 2 × 0.0109)
= Exp(6.8857)
= $978.19
Description
- The secondary trend is increasing.
- The growth rate of the secondary trend is 13.71% per annum.
- COST price at the close of October 30, 2026 was inside the secondary price channel.