Biogen Inc. (BIIB) vs Pfizer Inc. (PFE): Which Is the Better Buy in 2026?
As of 2026-06-19, BIIB is undervalued at $197, with a DCF intrinsic value of $735 and a margin of safety of 73%. PFE is overvalued at $25, with an intrinsic value of $22 and a margin of safety of -12%. Of the two, BIIB has the wider margin of safety.
Rewards
- ★Gross margin of 78.7% indicates strong pricing power — typical of businesses with significant intellectual property or brand strength.
- ★Free cash flow has grown at a 19.9% CAGR over the past 4 years, demonstrating strong earnings power growth.
- ★Gross margin of 74.8% indicates strong pricing power — typical of businesses with significant intellectual property or brand strength.
- ★FCF yield of 8.6% is historically attractive — the business generates significant cash relative to its price.
- ★Trailing P/E of 19.2x is 37% below the historical average of 30.4x — potentially undervalued relative to its own history.
Risks
- ⚠FCF yield of 6.7% suggests reasonable valuation assuming continued moderate growth.
- ⚠PEG ratio of 3.94 indicates the stock is expensive relative to its expected growth — the market may be pricing in more growth than analysts project.
- ⚠ROIC has declined by 15.9 percentage points over the past 4 years, which may signal competitive erosion.
- ⚠PEG ratio of 13.77 indicates the stock is expensive relative to its expected growth — the market may be pricing in more growth than analysts project.
- ⚠Free cash flow has declined at a 29.6% CAGR over the past 4 years — a concerning trend.
Key Valuation Metrics
Learn more →Historical Fundamentals
Learn more →Price ÷ Earnings Per Share — how many years of current earnings you're paying for at today's price. Lower P/E may indicate undervaluation. The dashed forward point is the forward P/E — today's price ÷ analyst consensus EPS.
Price ÷ Earnings Per Share — how many years of current earnings you're paying for at today's price. Lower P/E may indicate undervaluation. The dashed forward point is the forward P/E — today's price ÷ analyst consensus EPS.
Price ÷ Earnings Per Share — how many years of current earnings you're paying for at today's price. Lower P/E may indicate undervaluation. The dashed forward point is the forward P/E — today's price ÷ analyst consensus EPS.
$1 Retained Earnings Test
Learn more →> $1 created per $1 retained = Value Creator · < $1 created = Value Destroyer
> $1 created per $1 retained = Value Creator · < $1 created = Value Destroyer
Buffett's "$1 Test": For every $1 of earnings retained, has management created at least $1 of market value?
> $1 created per $1 retained = Value Creator · < $1 created = Value Destroyer
Discounted Cash Flow (DCF) Analysis
Learn more →Reverse DCF — Market-Implied Growth
Learn more →What growth rate is the market pricing in at $197?
The market implies +5.5% Owner Earnings growth, above historical trends.
Standard FCF implies a demanding +4.8%, reflecting heavy growth investment.
What growth rate is the market pricing in at $25?
The market implies +5.2% Owner Earnings growth, above historical trends.
Standard FCF implies a demanding +4.5%, reflecting heavy growth investment.
Economic Moat Score
Learn more →Narrow moat with margin stability as the key competitive advantage. Improving roic consistency would strengthen the moat.
No durable moat detected, though reinvestment efficiency shows some competitive positioning. The business lacks consistent evidence of sustainable advantages.
Forensic Accounting
Learn more →M-Score Trend
M-Score Trend
Beneish's 8-variable model estimates the probability of earnings manipulation. An M-Score above -1.78 signals elevated risk — companies in this range have historically been 3-5× more likely to be manipulating earnings. Scores between -2.22 and -1.78 fall in a grey zone warranting further investigation.
Ownership Breakdown
Learn more →High insider ownership aligns management incentives with shareholders. Institutional concentration can indicate smart-money conviction but also crowding risk.
Insider Buying Activity
Learn more →Open market purchases · includes direct & indirect ownership · excludes option exercises.
Insider Selling Activity
Learn more →Direct ownership only · excludes indirect, option exercises, planned (10b5-1) sales & derivatives.
🎭 Mr. Market's Mood
Learn more →"Market is optimistic — be cautious and ensure you have a margin of safety"
"Market is pricing this stock without strong emotion in either direction"
Composite sentiment score based on market signals. Inspired by Buffett’s "Mr. Market" allegory — fear = potential opportunity, greed = potential risk. Must be used alongside fundamental analysis, not in isolation.
⚖️ Buffett Signal
Learn more →The Buffett Signal cross-references market sentiment with DCF valuation. Configure the DCF Analysis above to generate a signal.
The Buffett Signal cross-references market sentiment with DCF valuation. Configure the DCF Analysis above to generate a signal.
Frequently Asked Questions: BIIB vs PFE
Is Biogen Inc. or Pfizer Inc. more undervalued in 2026?▼
Based on our discounted cash flow model, BIIB trades at a 73.3% margin of safety (intrinsic value $735 vs. price $197), compared to PFE's -12.3% margin of safety (intrinsic $22 vs. $25).
Which stock has a wider economic moat, Biogen Inc. or Pfizer Inc.?▼
BIIB scores 55/100 (Narrow moat), while PFE scores 35/100 (None moat). The moat score measures competitive advantage durability across ROIC consistency, margin stability, revenue predictability, and reinvestment efficiency.
Is Pfizer Inc. in financial distress?▼
PFE's Altman Z-Score of 2.1 places it in the Grey zone, signaling elevated bankruptcy risk. BIIB scores 3.2 (Safe zone). The Altman Z-Score is a five-factor model that predicts insolvency within two years; scores below 1.81 indicate significant distress.
Which company has better free cash flow, Biogen Inc. or Pfizer Inc.?▼
Pfizer Inc. (PFE) generates a 8.6% free cash flow yield, compared to Biogen Inc.'s 6.7%. A higher FCF yield means the business converts more of its market value into cash that can be returned to shareholders or reinvested.
Which stock has higher return on invested capital, Biogen Inc. or Pfizer Inc.?▼
PFE earns 10.2% ROIC versus BIIB's 7.1%. A higher ROIC means the company generates more profit per dollar of capital employed, a hallmark of durable competitive advantage in Buffett-style analysis.