Apple Inc. (AAPL) vs Quest Diagnostics Incorporated (DGX): Which Is the Better Buy in 2026?
As of 2026-09-17, AAPL is overvalued at $333, with a DCF intrinsic value of $172 and a margin of safety of -94%. DGX is overvalued at $247, with an intrinsic value of $149 and a margin of safety of -66%. Of the two, DGX has the wider margin of safety.
Rewards
- ★Apple Inc. has maintained ROIC above 15% for 4 consecutive years, indicating a durable competitive advantage.
- ★Apple Inc. scores 96/100 on the Economic Moat Score (Wide Moat), with roic consistency as the strongest competitive dimension.
- ★Return on equity has consistently exceeded 20% over 4 years, indicating efficient use of shareholder capital.
Risks
- ⚠FCF yield of 2.2% is below 3%, meaning the market is pricing in substantial future growth to justify the current price.
- ⚠PEG ratio of 2.67 indicates the stock is expensive relative to its expected growth — the market may be pricing in more growth than analysts project.
- ⚠5 insider sales totaling $2.2M with no purchases in the past 3 months — insiders are reducing their exposure.
- ⚠Each dollar of retained earnings has produced only $0.36 of earning power — shareholders may have been better served by dividends.
- ⚠Trailing P/E of 26.3x is 37% above the historical average of 19.1x — the stock trades at a premium to its own history.
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 $333?
The market implies +18.3% Owner Earnings growth, above historical trends.
Standard FCF implies a demanding +18.9%, reflecting heavy growth investment.
What growth rate is the market pricing in at $247?
The market implies +14.1% Owner Earnings growth, above historical trends.
Standard FCF implies a demanding +10.4%, reflecting heavy growth investment.
Economic Moat Score
Learn more →Wide moat with strength across all dimensions. ROIC Consistency is the standout factor.
Narrow moat with margin stability as the key competitive advantage. Improving roic consistency would strengthen the moat.
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 optimistic — be cautious and ensure you have a margin of safety"
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: AAPL vs DGX
Is Apple Inc. or Quest Diagnostics Incorporated more undervalued in 2026?▼
Based on our discounted cash flow model, DGX trades at a -65.9% margin of safety (intrinsic value $149 vs. price $247), compared to AAPL's -94.1% margin of safety (intrinsic $172 vs. $333).
Which stock has a wider economic moat, Apple Inc. or Quest Diagnostics Incorporated?▼
AAPL scores 96/100 (Wide moat), while DGX scores 56/100 (Narrow moat). The moat score measures competitive advantage durability across ROIC consistency, margin stability, revenue predictability, and reinvestment efficiency.
Which company has better free cash flow, Apple Inc. or Quest Diagnostics Incorporated?▼
Quest Diagnostics Incorporated (DGX) generates a 5.0% free cash flow yield, compared to Apple Inc.'s 2.2%. 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, Apple Inc. or Quest Diagnostics Incorporated?▼
AAPL earns 62.7% ROIC versus DGX's 9.7%. 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, Apple Inc.'s or Quest Diagnostics Incorporated's?▼
DGX's dividend earns a safety score of 94/100 (Very Safe), compared to AAPL's 94/100 (Very Safe). DGX has raised its dividend for 3 consecutive years.