Case Study: Using Price to Earnings to Uncover Investment Opportunities

Case Study: Using Price to Earnings to Uncover Investment Opportunities

Price to earnings is the ratio that dominates financial media, retail investing forums, and analyst reports. It is also the ratio that is most frequently misused. The price to earnings ratio divides the current stock price by earnings per share, giving you a multiple that tells you how much the market is paying for each dollar of profit. A P/E of 20 means you are paying $20 for every $1 of annual earnings. The number is easy to calculate and easy to cite, which is exactly why it leads so many investors in the wrong direction.

This case study walks through three real companies, Coca-Cola, Apple, and Berkshire Hathaway, to show where P/E works as a screening signal and where it fails. You will see how we use it inside our screener alongside ROIC, earnings quality flags, and Altman Z-Score to build a complete picture.

Key Takeaways

• Price to earnings is a starting point, not a conclusion. A low P/E can mean cheap or broken; a high P/E can mean quality or speculation. Context determines which.
• Coca-Cola's P/E of 23.7 looks high until you factor in 62 consecutive years of dividend growth and a brand moat that generates consistent free cash flow.
• Apple's P/E of 28.3 is justified by ROIC of 45.1%, one of the highest among large-cap companies globally.
• Berkshire Hathaway's P/E of 9.8 is deceptive because Buffett's operating model generates value through book value growth, not maximizing reported earnings.
• EPS is the most manipulable line on the income statement. Always cross-check with free cash flow per share before treating a low P/E as a value signal.
• The VMCI Score combines Value (35%), Quality (30%), Integrity (15%), Growth (12%), and Risk (8%) to catch the cases where a low P/E is a value trap, not an opportunity.

Case Study 1: Coca-Cola and the Quality P/E

Coca-Cola (KO) trades at a trailing P/E near 23.7 as of April 2026, with a dividend yield of 3.0%. At first glance, 23.7x looks expensive for a company growing organic revenue at roughly 5-7% per year. A naive screener would filter KO out as overvalued relative to its growth rate.

The right frame is different. Coca-Cola has paid and grown its dividend for 62 consecutive years. Its business model generates predictable free cash flow across recessions, pandemics, and geopolitical shocks. The brand operates in 200+ countries with a distribution network that would cost tens of billions to replicate from scratch. Pricing power is real: KO raised prices 9% in 2022-2023 while volume held steady, meaning consumers absorbed the increase without switching.

When you compare KO's P/E to its own 10-year historical range rather than the market average, the picture sharpens. KO has traded between 20x and 30x trailing earnings over the past decade. At 23.7x, it is in the lower third of its historical range, which is a different signal than 23.7x for a company that has never traded below 30x.

The earnings quality check matters here too. KO's earnings are backed by free cash flow. Net income over the trailing 12 months runs approximately $10.7 billion. Operating cash flow runs close to $11.2 billion. The cash conversion is above 100%, meaning the company earns more cash than it reports as net income. That is a clean earnings quality signal. The Beneish M-Score for KO sits well below the -1.78 manipulation threshold, consistently.

Case Study 2: Apple and the High-Quality Growth P/E

Apple (AAPL) trades at a trailing P/E of 28.3. By traditional value investing standards, paying 28x earnings for any company requires a strong justification. Apple's justification is its ROIC of 45.1%.

ROIC measures how efficiently a business converts invested capital into profit. A company with ROIC above its cost of capital creates value. A company with ROIC of 45% creates enormous value, because every dollar it retains and reinvests generates $0.45 of annual profit. Most mature businesses operate at 8-12% ROIC. Apple's 45.1% is not an accident; it reflects the iPhone's recurring revenue model, the services segment (App Store, Apple One, iCloud) growing at 13%+ annually, and a capital-light business model that generates approximately $100 billion in free cash flow per year on a relatively small asset base.

The P/E-to-ROIC relationship is the key insight here. You should expect to pay more for a business that compounds capital at 45% than for one compounding at 12%. The premium is warranted when the ROIC is durable. Apple's ROIC has been above 30% for 10 consecutive years, which is the durability test.

*Berkshire's P/E and ROIC require a different analytical framework, covered in Case Study 3 below.

Case Study 3: Berkshire Hathaway and When P/E Misleads

Berkshire Hathaway's B shares (BRK.B) trade at a trailing P/E of 9.8 and a price-to-book of 1.5. On a pure P/E basis, it looks deeply cheap. The reality is more nuanced.

Berkshire does not maximize reported earnings. Warren Buffett deliberately pays lower dividends, reinvests aggressively, and holds large amounts of cash (over $160 billion as of Q1 2026) that earns interest income rather than being deployed into operating businesses. The reported net income includes mark-to-market swings on the $300+ billion equity portfolio, which means Berkshire's P/E in any given year can swing wildly based on whether Apple stock rose or fell, not based on the operating businesses themselves.

The better metric for Berkshire is price-to-book value. At P/B of 1.5, you are paying 1.5x the net asset value of the company. Buffett has publicly stated he considers buybacks when BRK.B trades below 1.2-1.3x book, which he treats as a floor below intrinsic value. The current 1.5x is slightly above that floor, suggesting the market is giving modest credit for the management quality premium.

The Altman Z-Score is unusually high for Berkshire because of its diversified conglomerate structure and its $160 billion cash position. Financial distress is essentially zero. But the P/E of 9.8 should not be read as a signal that Berkshire is cheap in the traditional sense. It is an artifact of accounting, not a valuation gap.

The Most Common Price to Earnings Mistakes

Most investors make three recurring errors with P/E ratios.

The first is comparing P/E across sectors without adjusting for capital intensity. A software company at P/E 35 and a steel manufacturer at P/E 8 are not comparable. The steel company deploys far more capital per dollar of earnings, earns lower ROIC, and faces higher cyclicality. The 35x software P/E may be cheaper on a fundamental basis.

The second is using trailing P/E for cyclical companies. Oil and gas producers, steel companies, and semiconductor equipment makers have earnings that swing 50-100% between cycle peaks and troughs. Buying a steel company at P/E 5 when earnings are at peak is often a trap; the forward P/E when earnings normalize can be 30x. Use normalized earnings or EV/EBITDA for cyclicals.

The third is ignoring share count changes. If a company earns $1 billion and has 100 million shares outstanding, EPS is $10. If it borrows $2 billion and buys back 50 million shares, EPS doubles to $20 even though operating profit is unchanged. The P/E halves from 20x to 10x because the share count shrank, not because the business improved. Always track EPS alongside total net income and total debt.

How to Screen for P/E Opportunities Using ValueMarkers

The P/E ratio works best as a filter to narrow a universe, not as a buy signal on its own. Here is the screening process we recommend:

1. Set a P/E ceiling relative to the sector median. For tech, a reasonable ceiling is 1.5x sector median. For consumer staples, 1.3x. This excludes clear speculation without requiring you to define an absolute cutoff.
2. Filter for ROIC above 15%. Below that threshold, the business may not be earning its cost of capital, and a low P/E is often low for good reason.
3. Check the earnings quality flag. Our screener surfaces the Beneish M-Score alongside each P/E. An M-Score above -1.78 means the reported earnings that generate the P/E may not be reliable.
4. Confirm with free cash flow yield. FCF yield should be within 1-2 percentage points of the earnings yield (1/P/E). A large gap between earnings yield and FCF yield means non-cash earnings are distorting the P/E.
5. Check the VMCI Score for the final pass. The Integrity pillar (15% of VMCI) catches the accounting issues that a P/E screen misses.

Is Coca-Cola a Good Stock to Buy Right Now

At a P/E of 23.7 and dividend yield of 3.0%, Coca-Cola is fairly valued on a historical basis. It is not cheap by the standards of 2020, when KO briefly touched 20x. It is not expensive by the standards of 2021-2022, when it traded near 28x. The question investors should ask is not whether KO is cheap relative to the S&P 500, but whether KO's earnings quality and dividend safety justify the current multiple relative to its own history.

The answer for a long-term holder is probably yes. The dividend is covered by free cash flow at roughly 75% payout ratio, which is sustainable. Organic revenue growth is running 5-7%, faster than nominal GDP in most markets. The Altman Z-Score is solidly in the safe zone. The 62-year dividend growth streak creates a behavioral anchor that keeps institutional holders from selling on small earnings misses.

For a value investor seeking a margin of safety, a better entry would be near P/E 20 or below, which has occurred roughly once every three to four years in the past decade. Running a price alert through our screener when KO's forward P/E drops below 20 is a disciplined way to wait without watching the stock daily.

Further reading: SEC EDGAR · FRED Economic Data

Why P/E ratio Matters

This section anchors the discussion on P/E ratio. The detailed treatment, formula, and worked examples appear in the body of this article above. The points below summarize the most important takeaways for value investors who want to apply P/E ratio in real portfolio decisions. ValueMarkers exposes the underlying data on every covered ticker via the screener and stock profile pages, so the concepts in this article translate directly into actionable filters.

Key inputs for P/E ratio

See the main discussion of P/E ratio in the sections above for the full treatment, including the inputs, the calculation methodology, the typical sector benchmarks, and the most common pitfalls to avoid. The ValueMarkers screener lets value investors filter the full universe of 100,000+ stocks across 73 exchanges using P/E ratio alongside the rest of the 120-indicator composite, with sector percentiles and historical trends shown on every stock profile.

Sector benchmarks for P/E ratio

See the main discussion of P/E ratio in the sections above for the full treatment, including the inputs, the calculation methodology, the typical sector benchmarks, and the most common pitfalls to avoid. The ValueMarkers screener lets value investors filter the full universe of 100,000+ stocks across 73 exchanges using P/E ratio alongside the rest of the 120-indicator composite, with sector percentiles and historical trends shown on every stock profile.

Related ValueMarkers Resources

• ROIC Consistency — ROIC Consistency measures how efficiently a company converts capital into earnings
• Earnings Quality — Glossary entry for Earnings Quality
• Altman Z-Score — Altman Z-Score is the metric used to the reliability of reported earnings versus underlying cash flow
• Nasdaq Earnings Calendar — related ValueMarkers analysis
• Earnings Schedule Nasdaq — related ValueMarkers analysis
• Asset Allocation Analyzer — related ValueMarkers analysis

Frequently Asked Questions

is coca cola a good stock to buy

Coca-Cola (KO) at a P/E of 23.7 and a 3.0% dividend yield is fairly valued relative to its own 10-year average multiple. The 62-year dividend growth streak, consistent free cash flow, and global distribution moat make it a high-quality holding. Whether it is a good buy at the current price depends on your required return: at 3.0% yield and 5-7% earnings growth, total returns of 8-10% annually are plausible, which is competitive with the S&P 500 average but with lower volatility.

what are earnings per share

Earnings per share is net income divided by diluted shares outstanding. Apple's trailing EPS of approximately $6.43 is calculated by dividing $94 billion in net income by roughly 15.5 billion diluted shares. EPS is the denominator in the P/E ratio. When companies buy back shares, EPS rises even without any improvement in profitability, because the same net income is spread across fewer shares. Always check whether EPS growth reflects real profit growth or share count reduction.

how to invest in stock options

Stock options are contracts that give you the right to buy or sell 100 shares of a stock at a specified price (the strike) before a specified date (the expiration). Long call options profit when the stock rises above the strike plus the premium paid. Long put options profit when the stock falls below the strike minus the premium. For value investors, options are most useful for generating income through covered calls on long positions or for reducing entry cost through cash-secured puts on stocks you want to own at a specific price.

what's equivalent to motley fool epic plus

Motley fool Epic Plus offers stock picks, portfolio guidance, and analyst commentary. ValueMarkers provides a fundamentally different approach: rather than curated picks, we give you the tools to make your own decisions with 120+ indicators across 73 global exchanges, including P/E, ROIC, Beneish M-Score, Altman Z-Score, and the VMCI Score. The screener lets you filter by any combination of fundamentals and find your own candidates using the same methodology that professional investors apply.

how to invest in private companies before they go public

Investing in private companies before an IPO is available through accredited investor platforms such as EquityZen, Forge Global, and AngelList. These platforms facilitate secondary sales of private company shares from early employees and investors. The risks are significant: private company financials are not publicly disclosed, liquidity is limited, and valuations are set by negotiation rather than market price discovery. Most value investing frameworks apply poorly to pre-IPO companies because the earnings history needed to calculate a reliable P/E does not exist.

what stocks to buy

The question is better framed as what process to use, because no single answer applies across investors with different time horizons, risk tolerances, and tax situations. The method that has produced consistent results in academic research and among long-term investors starts with ROIC above 15%, P/E below 25x for the sector, free cash flow yield above 3%, and an Altman Z-Score in the safe zone. Running that filter through our screener across 73 global exchanges gives you a starting list of businesses worth deeper study, not a buy list, but a research list.

Run the P/E filter alongside ROIC, earnings quality, and the Altman Z-Score in our screener to build a research list grounded in fundamentals rather than headlines.

Written by Javier Sanz, Founder of ValueMarkers. Last updated April 2026.

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Disclaimer: This content is for informational and educational purposes only and does not constitute investment advice, a recommendation, or an offer to buy or sell any security. Past performance does not guarantee future results. Consult a licensed financial advisor before making investment decisions.