Piotroski F-Score: The 9-Point System for Finding Strong Stocks
Not every cheap stock deserves to be bought. A low price-to-book ratio can reflect a genuinely undervalued business -- or a business that is deteriorating and rightly deserves a discount. The Piotroski F-Score was designed to solve exactly this problem: separating financially strong value stocks from the ones that are cheap for good reason.
This guide covers every one of the nine criteria, explains the accounting logic behind each signal, and shows how to use the ValueMarkers Piotroski Calculator to apply the framework to any stock.
The Origin of the Piotroski F-Score
In 2000, accounting professor Joseph Piotroski published a paper in the Journal of Accounting Research titled "Value Investing: The Use of Historical Financial Statement Information to Separate Winners from Losers." The core finding: among stocks with low price-to-book ratios (the classic value signal), financial statement analysis could reliably identify which ones would outperform and which would disappoint.
Piotroski built a scoring system using nine binary signals drawn entirely from publicly available financial statements. Each signal scores 1 if the company passes and 0 if it fails. The total score ranges from 0 (weakest) to 9 (strongest).
His backtesting showed that buying high-scoring stocks (F-Score of 8 or 9) while shorting low-scoring ones (F-Score of 0 or 1) generated a mean annual return of 23% over the 1976-1996 study period. The long-only strategy -- simply avoiding the weakest-scoring value stocks -- outperformed the broader value universe by roughly 7.5% annually.
The framework has been replicated and validated in dozens of subsequent academic studies across US and international markets.
The Three Pillars of the F-Score
The nine signals are organized into three categories, each probing a different dimension of financial health.
Pillar 1: Profitability (4 signals)
Profitability signals measure whether the business is generating returns from its assets and whether those returns are improving.
Signal 1: Return on Assets (ROA) Score 1 point if net income before extraordinary items divided by beginning-of-year total assets is positive.
A positive ROA means the company is generating profit from the asset base it has deployed. This is the baseline test -- if ROA is negative, the business is running at a loss, which is a serious red flag for a value stock.
Signal 2: Operating Cash Flow (CFO) Score 1 point if cash flow from operations is positive.
Operating cash flow is harder to manipulate than net income. Earnings can be inflated through revenue recognition timing, depreciation choices, and other accounting adjustments. Cash flow from operations cuts through much of this noise. A company with positive net income but negative operating cash flow may be booking revenue it has not yet collected.
Signal 3: Change in Return on Assets (Delta ROA) Score 1 point if ROA this year is higher than ROA last year.
Improvement in ROA signals that the business is becoming more productive over time. Stable or improving profitability is a fundamentally different situation from a company whose returns are eroding, even if both have positive ROA at the moment.
Signal 4: Accruals (Quality of Earnings) Score 1 point if operating cash flow divided by total assets is greater than ROA (i.e., cash flow from operations exceeds net income).
This is the accruals or earnings quality signal. When net income exceeds operating cash flow, the difference is accruals -- revenue that has been recognized on the income statement but has not yet arrived as cash. High accruals are associated with lower earnings quality and weaker future performance. The Sloan (1996) accruals anomaly documented that high-accrual stocks significantly underperform low-accrual stocks in subsequent years.
A score of 1 here means cash earnings exceed accrual earnings -- a sign of high-quality, conservatively reported profits.
Pillar 2: Leverage, Liquidity, and Source of Funds (3 signals)
These signals test whether the company's balance sheet is becoming stronger or weaker.
Signal 5: Change in Leverage (Delta Leverage) Score 1 point if the long-term debt-to-average-assets ratio decreased compared to the prior year.
Rising leverage means the company is taking on more debt relative to its asset base. For a value stock that is already trading at a depressed price, increasing financial risk compounds the downside. A decrease in leverage signals that the company is managing its balance sheet responsibly.
Signal 6: Change in Liquidity (Delta Liquidity) Score 1 point if the current ratio (current assets divided by current liabilities) improved compared to the prior year.
The current ratio measures short-term solvency -- the ability to meet obligations coming due within a year. An improving current ratio indicates the company is in a better position to weather near-term headwinds. A declining current ratio in an already-cheap stock is a warning sign.
Signal 7: Absence of Dilution (No New Share Issuance) Score 1 point if the company did not issue new common shares in the past year.
When a company issues new shares, it dilutes existing shareholders. Established companies that cannot fund their operations or growth from internal cash flows and must instead turn to equity markets are a red flag. Piotroski found that share issuance was negatively correlated with future performance among value stocks. Companies that did not dilute shareholders over the prior year scored 1.
Pillar 3: Operating Efficiency (2 signals)
Efficiency signals measure whether the business is generating more revenue and profit from its assets and cost structure.
Signal 8: Change in Gross Margin (Delta Gross Margin) Score 1 point if gross profit margin improved compared to the prior year.
Gross margin improvement can reflect pricing power (the company is raising prices without losing volume), cost efficiency (input costs are falling), or a mix shift toward higher-margin products. Any of these is a positive signal about competitive position and earnings trajectory.
Signal 9: Change in Asset Turnover (Delta Asset Turnover) Score 1 point if asset turnover (revenue divided by total assets) improved compared to the prior year.
Rising asset turnover means the company is generating more revenue per dollar of assets deployed. This indicates improving operational efficiency and is associated with better future returns on equity.
How to Interpret Your F-Score
| Score | Interpretation | Suggested Action |
|---|---|---|
| 8-9 | Financially strong; fundamentals improving across the board | Strong buy candidate (combined with valuation check) |
| 6-7 | Above average; most criteria passing | Acceptable; investigate the failing signals |
| 4-5 | Average; mixed signals | Caution; the business is neither deteriorating nor strengthening |
| 2-3 | Below average; multiple red flags | Avoid or underweight; high risk of continued underperformance |
| 0-1 | Financially weak; fundamental deterioration across most measures | Avoid; typical of distressed or fraudulent companies |
A few important caveats:
The F-Score is a screening tool, not a verdict. A score of 8 does not guarantee outperformance. It identifies a higher probability of financial improvement among value stocks. Use it as a filter to narrow your universe, not as the sole basis for a buy decision.
Context matters by industry. Banks, insurers, and REITs use different accounting frameworks from industrial companies. The leverage signals in particular require adjustment for financial sector companies, where some forms of leverage are the core business model.
Pair it with valuation. Piotroski's original research was conducted on a universe of low-price-to-book stocks. The F-Score works best as a quality filter within a value-screened universe. A high F-Score on an expensive stock is still an expensive stock. Cross-reference with the ValueMarkers DCF Calculator or the Margin of Safety Calculator to confirm the price is reasonable.
Worked Example: Comparing Two Value Stocks
Imagine two stocks both trading at a price-to-book ratio of 0.9. On the surface, they look equally cheap. The F-Score reveals the difference.
Company A:
- ROA positive: 1
- CFO positive: 1
- ROA improving: 1
- Cash earnings > accrual earnings: 1
- Leverage decreasing: 1
- Liquidity improving: 0
- No new share issuance: 1
- Gross margin improving: 1
- Asset turnover improving: 1
- F-Score: 8
Company B:
- ROA positive: 1
- CFO positive: 0
- ROA improving: 0
- Cash earnings > accrual earnings: 0
- Leverage decreasing: 0
- Liquidity improving: 0
- No new share issuance: 0
- Gross margin improving: 1
- Asset turnover improving: 0
- F-Score: 2
Same price-to-book ratio, completely different fundamental trajectories. Company A shows a business that is profitable, cash-generative, reducing debt, and becoming more efficient. Company B shows declining profitability, cash burn, rising leverage, and dilution. Buying Company A and avoiding Company B is precisely what the F-Score was designed to enable.
Backtesting Evidence
Piotroski's original 2000 study showed compelling results, but the real test is whether the findings hold up out-of-sample and across different markets.
Studies replicating Piotroski's work in European markets, Asian markets, and more recent US data generally confirm the direction of the findings, though the magnitude varies:
- Hyde (2013) found similar results for UK stocks.
- Walkshausl (2013) confirmed the F-Score premium in international developed markets.
- Studies covering the 2000s and 2010s found smaller but still statistically significant alpha from the F-Score, consistent with the signal becoming partially priced in as it gained wider adoption.
The evidence suggests the F-Score is most powerful in markets with less analyst coverage (small-cap, international) where financial statement information is less efficiently priced. In large-cap US equities, the signal is weaker but still positive.
A practical implication: use the F-Score most aggressively when screening small and mid-cap stocks, and combine it with other tools for mega-cap analysis.
Where the F-Score Has Limits
No single model captures everything. The Piotroski F-Score has well-documented limitations:
It looks backward. All nine signals are based on historical financial statement data. A company can score 9 today and deteriorate next quarter if competitive conditions change, a major customer is lost, or macro conditions shift.
It does not measure valuation. A company can have an F-Score of 9 and still be expensive. The score tells you about financial quality and trajectory, not whether the price is right.
Industry distortions. As noted above, financial sector companies require separate treatment. High leverage is a business model feature for banks, not a red flag.
It does not detect fraud. A company committing accounting fraud may score relatively well on some signals because the fraud inflates reported earnings and cash flows. For fraud detection, the Beneish M-Score and Altman Z-Score are more targeted tools.
One-off events. A single quarter of asset sales, a large write-down, or a tax benefit can shift multiple signals simultaneously. Always verify the underlying source when a score changes dramatically in a single year.
Using the Piotroski F-Score with ValueMarkers
The ValueMarkers Piotroski Calculator computes the F-Score for any covered stock automatically, breaking down all nine signals so you can see exactly which criteria the company passes and fails. This is more useful than just the total score -- the composition tells you where the business is healthy and where it is showing cracks.
The ValueMarkers screener lets you filter the full universe by F-Score alongside 120+ other indicators, so you can screen for, say, F-Score of 7 or higher combined with price-to-book below 1.5 and free cash flow yield above 5% in a single query across 73 global exchanges.
For a complete fundamental workflow:
- Screen for low-valuation stocks using the leaderboard or screener filters.
- Run the F-Score to identify which candidates have improving fundamentals.
- Validate intrinsic value with the DCF Calculator.
- Check your margin of safety with the Margin of Safety Calculator.
- Monitor quarterly for any F-Score deterioration.
Ready to score your stock picks? Use the ValueMarkers Piotroski Calculator to run the full 9-signal analysis on any ticker, or screen by F-Score in the ValueMarkers Screener.
Written by Javier Sanz, Founder of ValueMarkers Last updated May 2026
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Disclaimer: Educational content -- not investment advice. 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.