Compare Stocks › MRK vs TMO

Merck & Co., Inc. (MRK) vs Thermo Fisher Scientific Inc. (TMO): Which Is the Better Buy in 2026?

As of 2026-11-01, MRK is undervalued at $150, with a DCF intrinsic value of $596 and a margin of safety of 75%. TMO is overvalued at $697, with an intrinsic value of $428 and a margin of safety of -63%. Of the two, MRK has the wider margin of safety.

MRK
Merck & Co., Inc.
$149.52
VS
TMO
Thermo Fisher Scientific Inc.
$697.00

Rewards

MRK
  • ★Gross margin of 76.9% indicates strong pricing power — typical of businesses with significant intellectual property or brand strength.
  • ★Each dollar of retained earnings has created $4.94 of earning power — management is an exceptional capital allocator.
  • ★Management has timed buybacks well — 2 out of 3 years showed value-accretive repurchases.
TMO
  • ★Altman Z-Score of 3.85 indicates very low bankruptcy risk — the company is firmly in the safe zone.

Risks

MRK
  • ⚠PEG ratio of 2.82 indicates the stock is expensive relative to its expected growth — the market may be pricing in more growth than analysts project.
  • ⚠7 insider sales totaling $30.0M with no purchases in the past 3 months — insiders are reducing their exposure.
  • ⚠Free cash flow has declined at a 5.6% CAGR over the past 4 years — a concerning trend.
TMO
  • ⚠FCF yield of 2.5% is below 3%, meaning the market is pricing in substantial future growth to justify the current price.
  • ⚠PEG ratio of 2.03 indicates the stock is expensive relative to its expected growth — the market may be pricing in more growth than analysts project.
  • ⚠7 insider sales totaling $41.2M with no purchases in the past 3 months — insiders are reducing their exposure.

Key Valuation Metrics

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MRK
TMO
Valuation
N/A
Free Cash Flow
$6.45B
N/A
FCF Yield
2.50%
151.03
Trailing P/E
36.76
16.44
Forward P/E
25.10
Quality & Moat
22.88%
ROIC
7.85%
43.48%
ROE
13.38%
76.91%
Gross Margin
41.17%
2.82
PEG Ratio
2.03
Balance Sheet Safety
1.11
Net Debt / Equity
0.64
N/A
Interest Coverage
N/A
2.93
Net Debt / EBITDA
2.89
2.27%
Dividend Yield
0.27%
MRK: 5Ties: 2TMO: 3
MRKTMO

Historical Fundamentals

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MRK

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.

TMO

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

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MRK
$-1.72
created per $1 retained over 3 years
Market Cap Declined
Σ Retained
$12.28B
Δ Market Cap
$-21.09B
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
TMO
$0.17
created per $1 retained over 3 years
Value Destroyer
Σ Retained
$17.29B
Δ Market Cap
+$2.95B
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

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

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MRK
74.9% Margin of Safety
Price is 74.9% below estimated fair value
Current Price: $149.52
Fair Value: $596.15
Strongly undervalued
Undervalued
Fairly valued
Overvalued
Strongly overvalued
TMO
62.8% Overvalued
Price is 62.8% above estimated fair value
Current Price: $697.00
Fair Value: $428.05
Strongly undervalued
Undervalued
Fairly valued
Overvalued
Strongly overvalued

Reverse DCF — Market-Implied Growth

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MRK

Requires positive FCF to compute implied growth rate.

TMO

What growth rate is the market pricing in at $697?

+16.0%
Market-Implied Owner Earnings Growth
Standard FCF implies +18.9%

The market implies +16.0% Owner Earnings growth, above historical trends.

Standard FCF implies a demanding +18.9%, reflecting heavy growth investment.

Economic Moat Score

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MRK
68/100
Narrow Moat
70+ Wide · 40-69 Narrow · <40 None

Narrow moat with revenue predictability as the key competitive advantage. Improving margin stability would strengthen the moat.

Composite score measuring competitive advantage durability across four dimensions: returns above cost of capital, pricing power stability, revenue predictability, and capital efficiency. Based on 4 years of fundamental data.
TMO
60/100
Narrow Moat
70+ Wide · 40-69 Narrow · <40 None

Narrow moat with margin stability as the key competitive advantage. Improving roic consistency would strengthen the moat.

Composite score measuring competitive advantage durability across four dimensions: returns above cost of capital, pricing power stability, revenue predictability, and capital efficiency. Based on 4 years of fundamental data.

Forensic Accounting

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MRK
-2.31
Unlikely Manipulator
Above -1.78 = likely manipulator · -2.22 to -1.78 = grey zone

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.
TMO
-2.47
Unlikely Manipulator
Above -1.78 = likely manipulator · -2.22 to -1.78 = grey zone

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.

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

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MRK
Insiders 0.1%Institutions 82.9%Retail & Other 17.1%
No. of Institutional Holders4,903
High insider ownership aligns management incentives with shareholders — a key signal in Buffett-style analysis. Institutional concentration can indicate smart-money conviction but also crowding risk.
TMO
Insiders 0.1%Institutions 93.5%Retail & Other 6.4%
No. of Institutional Holders3,657
High insider ownership aligns management incentives with shareholders — a key signal in Buffett-style analysis. Institutional concentration can indicate smart-money conviction but also crowding risk.

High insider ownership aligns management incentives with shareholders. Institutional concentration can indicate smart-money conviction but also crowding risk.

Insider Buying Activity

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MRK
0
Buys (3M)
0
Buys (12M)
THULIN INGE G
Director
$250,000
@ $88.28 · 2025-02-06
BAKER DOUGLAS M JR
Director
$1.33M
@ $88.50 · 2025-02-05
Open market purchases · includes direct & indirect ownership · excludes option exercises
TMO
0
Buys (3M)
0
Buys (12M)
CHAI NELSON J
Director
$11,038
@ $551.90 · 2024-12-09
Open market purchases · includes direct & indirect ownership · excludes option exercises

Open market purchases · includes direct & indirect ownership · excludes option exercises.

Insider Selling Activity

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MRK
7
Sells (3M)
21
Sells (12M)
Total value (12M): $72.01M
GUINDO CHIRFI
Officer
$1.35M
@ $135.00 · 2026-08-13
ZACHARY JENNIFER L
General Counsel
$10.72M
@ $133.46 · 2026-08-12
DELUCA RICHARD ROBERT JR.
Officer
$5.94M
@ $131.12 · 2026-08-12
GUINDO CHIRFI
Officer
$1.97M
@ $131.00 · 2026-08-06
DELUCA RICHARD ROBERT JR.
Officer
$788,773
@ $130.38 · 2026-08-06
MARALDO DAVID R.
Officer
$2.41M
@ $128.72 · 2026-08-05
WILLIAMS DAVID MICHAEL
Chief Technology Officer
$6.81M
@ $128.77 · 2026-08-05
GUINDO CHIRFI
Officer
$1.21M
@ $121.46 · 2026-02-12
LI DEAN Y
Officer
$1.20M
@ $117.52 · 2026-02-10
GUINDO CHIRFI
Officer
$1.18M
@ $118.41 · 2026-02-09
ZACHARY JENNIFER L
General Counsel
$14.49M
@ $119.15 · 2026-02-09
WILLIAMS DAVID MICHAEL
Chief Technology Officer
$609,525
@ $121.91 · 2026-02-06
OOSTHUIZEN JOHANNES JACOBUS
Officer
$1.83M
@ $121.87 · 2026-02-06
DELUCA RICHARD ROBERT JR.
Officer
$4.56M
@ $120.92 · 2026-02-06
GUINDO CHIRFI
Officer
$2.44M
@ $121.88 · 2026-02-05
LI DEAN Y
Officer
$1.79M
@ $118.77 · 2026-02-04
LITCHFIELD CAROLINE
Chief Financial Officer
$5.02M
@ $119.61 · 2026-02-04
SMART DALTON E. III
Officer
$765,920
@ $119.67 · 2026-02-04
DAVIS ROBERT M
Chief Executive Officer
$5.60M
@ $118.04 · 2026-02-04
DOWNING CRISTAL N.
Officer
$616,395
@ $87.00 · 2025-11-10
WILLIAMS DAVID MICHAEL
Chief Technology Officer
$720,040
@ $83.59 · 2025-11-03
SMART DALTON E. III
Officer
$352,723
@ $82.76 · 2025-04-25
OOSTHUIZEN JOHANNES JACOBUS
Officer
$714,745
@ $84.09 · 2025-02-19
WILLIAMS DAVID MICHAEL
Chief Technology Officer
$512,057
@ $85.34 · 2025-02-13
DOWNING CRISTAL N.
Officer
$209,551
@ $88.76 · 2025-02-06
Direct ownership only · excludes indirect, option exercises, planned (10b5-1) sales & derivatives
TMO
7
Sells (3M)
21
Sells (12M)
Total value (12M): $123.88M
PETTITI GIANLUCA
President
$2.54M
@ $614.38 · 2026-08-31
CASPER MARC N
Chief Executive Officer
$172,439
@ $627.05 · 2026-08-24
CASPER MARC N
Chief Executive Officer
$12.56M
@ $628.09 · 2026-08-21
BRITT LISA P
Officer
$7.01M
@ $613.12 · 2026-08-19
SHAFER MICHAEL D
Officer
$15.30M
@ $600.00 · 2026-08-11
HOLMES JOSEPH R.
Officer
$245,620
@ $584.81 · 2026-08-07
BRITT LISA P
Officer
$3.39M
@ $580.00 · 2026-08-06
PETTITI GIANLUCA
President
$226,000
@ $565.00 · 2026-07-27
PETTITI GIANLUCA
President
$185,064
@ $462.66 · 2026-04-27
SHAFER MICHAEL D
Officer
$802,536
@ $499.40 · 2026-03-11
CASPER MARC N
Chief Executive Officer
$2.06M
@ $514.82 · 2026-03-05
CASPER MARC N
Chief Executive Officer
$5.08M
@ $507.75 · 2026-03-04
PETTITI GIANLUCA
Officer
$216,480
@ $541.20 · 2026-02-09
LAGARDE MICHEL
Chief Operating Officer
$12.42M
@ $563.56 · 2025-12-04
LAGARDE MICHEL
Chief Operating Officer
$36.13M
@ $582.68 · 2025-12-03
LOWERY FREDERICK M.
Officer
$8.15M
@ $589.81 · 2025-12-02
SHAFER MICHAEL D
Officer
$6.43M
@ $600.00 · 2025-11-25
LAGARDE MICHEL
Chief Operating Officer
$2.76M
@ $594.42 · 2025-11-13
BRITT LISA P
Officer
$622,136
@ $588.59 · 2025-11-12
PETTITI GIANLUCA
Officer
$1.73M
@ $580.00 · 2025-11-10
BRITT LISA P
Officer
$5.84M
@ $571.62 · 2025-11-07
CASPER MARC N
Chief Executive Officer
$13.91M
@ $571.33 · 2025-10-27
PETTITI GIANLUCA
Officer
$229,660
@ $574.15 · 2025-10-24
CASPER MARC N
Chief Executive Officer
$200,201
@ $500.50 · 2025-09-05
HOLMES JOSEPH R.
Officer
$189,662
@ $492.63 · 2025-08-29
CASPER MARC N
Chief Executive Officer
$5.01M
@ $500.96 · 2025-08-22
CASPER MARC N
Chief Executive Officer
$248,046
@ $500.09 · 2025-08-20
CASPER MARC N
Chief Executive Officer
$8.15M
@ $452.99 · 2025-08-07
PETTITI GIANLUCA
Officer
$191,992
@ $479.98 · 2025-07-25
PETTITI GIANLUCA
Officer
$164,444
@ $411.11 · 2025-05-12
PETTITI GIANLUCA
Officer
$128,979
@ $429.93 · 2025-04-28
BOXER MICHAEL A
General Counsel
$2.01M
@ $532.59 · 2025-03-10
CASPER MARC N
Chief Executive Officer
$9.33M
@ $518.16 · 2025-03-05
SHAFER MICHAEL D
Officer
$945,038
@ $530.92 · 2025-03-03
LOWERY FREDERICK M.
Officer
$9.73M
@ $531.81 · 2025-02-24
CHAI NELSON J
Director
$8,449
@ $528.06 · 2025-02-19
PETTITI GIANLUCA
Officer
$175,677
@ $585.59 · 2025-02-04
WILLIAMSON STEPHEN
Chief Financial Officer
$11.58M
@ $589.36 · 2025-02-04
CASPER MARC N
Chief Executive Officer
$10.62M
@ $531.23 · 2024-12-03
Direct ownership only · excludes indirect, option exercises, planned (10b5-1) sales & derivatives

Direct ownership only · excludes indirect, option exercises, planned (10b5-1) sales & derivatives.

🎭 Mr. Market's Mood

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MRK
FearGreed
😏Greed(65/100)

"Market is optimistic — be cautious and ensure you have a margin of safety"

Composite sentiment score based on 6 market signals. Inspired by Buffett's "Mr. Market" allegory — fear = potential opportunity, greed = potential risk. Must be used alongside fundamental analysis, not in isolation.
TMO
FearGreed
😏Greed(69/100)

"Market is optimistic — be cautious and ensure you have a margin of safety"

Composite sentiment score based on 6 market signals. Inspired by Buffett's "Mr. Market" allegory — fear = potential opportunity, greed = potential risk. Must be used alongside fundamental analysis, not in isolation.

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

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MRK
⚪Awaiting DCF Data

The Buffett Signal cross-references market sentiment with DCF valuation. Configure the DCF Analysis above to generate a signal.

DCF Margin of Safety: N/AMr. Market's Mood: Greed (65)
TMO
⚪Awaiting DCF Data

The Buffett Signal cross-references market sentiment with DCF valuation. Configure the DCF Analysis above to generate a signal.

DCF Margin of Safety: N/AMr. Market's Mood: Greed (69)
View MRK Full AnalysisView TMO Full Analysis

Frequently Asked Questions: MRK vs TMO

Is Merck & Co., Inc. or Thermo Fisher Scientific Inc. more undervalued in 2026?▼

Based on our discounted cash flow model, MRK trades at a 74.9% margin of safety (intrinsic value $596 vs. price $150), compared to TMO's -62.8% margin of safety (intrinsic $428 vs. $697).

Which stock has a wider economic moat, Merck & Co., Inc. or Thermo Fisher Scientific Inc.?▼

MRK scores 68/100 (Narrow moat), while TMO scores 60/100 (Narrow moat). The moat score measures competitive advantage durability across ROIC consistency, margin stability, revenue predictability, and reinvestment efficiency.

Which stock has higher return on invested capital, Merck & Co., Inc. or Thermo Fisher Scientific Inc.?▼

MRK earns 22.9% ROIC versus TMO's 7.8%. A higher ROIC means the company generates more profit per dollar of capital employed, a hallmark of durable competitive advantage in Buffett-style analysis.

Which dividend is safer, Merck & Co., Inc.'s or Thermo Fisher Scientific Inc.'s?▼

TMO's dividend earns a safety score of 94/100 (Very Safe), compared to MRK's 79/100 (Safe). TMO has raised its dividend for 3 consecutive years.