Biogen Inc (BIIB)
Biogen Inc. is an American multinational biotechnology company based in Cambridge, Massachusetts, specializing in the discovery, development, and delivery of therapies for the treatment of neurological diseases to patients worldwide.
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 33.73% per annum.
- BIIB price at the close of August 25, 2025 was $136.36 and was inside the primary price channel.
- The secondary trend is increasing.
- The growth rate of the secondary trend is 42.22% per annum.
- BIIB price at the close of August 25, 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 BIIB 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: April 13, 2023
End date: August 14, 2025
a = 6.8549
b = -0.0011
s = 0.0780
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × -0.0011) – 1
= -33.73%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0780) – 1
= 36.63%
April 13, 2023 calculations
Top border of price channel:
Exp(Y661)
= Exp(a + b × X661 + 2 × s)
= Exp(a + b × 960 + 2 × s)
= Exp(6.8549 + -0.0011 × 960 + 2 × 0.0780)
= Exp(5.9290)
= $375.77
Bottom border of price channel:
Exp(Y661)
= Exp(a + b × X661 – 2 × s)
= Exp(a + b × 960 – 2 × s)
= Exp(6.8549 + -0.0011 × 960 – 2 × 0.0780)
= Exp(5.6169)
= $275.02
August 14, 2025 calculations
Top border of price channel:
Exp(Y1,247)
= Exp(a + b × X1,247 + 2 × s)
= Exp(a + b × 1,814 + 2 × s)
= Exp(6.8549 + -0.0011 × 1,814 + 2 × 0.0780)
= Exp(4.9664)
= $143.51
Bottom border of price channel:
Exp(Y1,247)
= Exp(a + b × X1,247 – 2 × s)
= Exp(a + b × 1,814 – 2 × s)
= Exp(6.8549 + -0.0011 × 1,814 – 2 × 0.0780)
= Exp(4.6543)
= $105.04
Description
- The primary trend is decreasing.
- The decline rate of the primary trend is 33.73% per annum.
- BIIB price at the close of August 25, 2025 was $136.36 and was inside the primary price channel.
Secondary Trend
Start date: April 4, 2025
End date: August 25, 2025
a = 3.1527
b = 0.0010
s = 0.0309
Annual growth rate:
Exp(365 × b) – 1
= Exp(365 × 0.0010) – 1
= 42.22%
Price channel spread:
Exp(4 × s) – 1
= Exp(4 × 0.0309) – 1
= 13.17%
April 4, 2025 calculations
Top border of price channel:
Exp(Y1,157)
= Exp(a + b × X1,157 + 2 × s)
= Exp(a + b × 1,682 + 2 × s)
= Exp(3.1527 + 0.0010 × 1,682 + 2 × 0.0309)
= Exp(4.8375)
= $126.15
Bottom border of price channel:
Exp(Y1,157)
= Exp(a + b × X1,157 – 2 × s)
= Exp(a + b × 1,682 – 2 × s)
= Exp(3.1527 + 0.0010 × 1,682 – 2 × 0.0309)
= Exp(4.7138)
= $111.47
August 25, 2025 calculations
Top border of price channel:
Exp(Y1,254)
= Exp(a + b × X1,254 + 2 × s)
= Exp(a + b × 1,825 + 2 × s)
= Exp(3.1527 + 0.0010 × 1,825 + 2 × 0.0309)
= Exp(4.9755)
= $144.82
Bottom border of price channel:
Exp(Y1,254)
= Exp(a + b × X1,254 – 2 × s)
= Exp(a + b × 1,825 – 2 × s)
= Exp(3.1527 + 0.0010 × 1,825 – 2 × 0.0309)
= Exp(4.8518)
= $127.97
Description
- The secondary trend is increasing.
- The growth rate of the secondary trend is 42.22% per annum.
- BIIB price at the close of August 25, 2025 was inside the secondary price channel.