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Financial StrengthF-Score

What is the Piotroski F-Score?

The Piotroski F-Score is a 9-point scoring system developed by Stanford professor Joseph Piotroski in 2000 to identify financially strong companies among value stocks. Each criterion scores 0 (fail) or 1 (pass). Score 8-9 = Strong, 6-7 = Improving, 0-2 = Weak. Backtested to deliver 7.5% annual outperformance when buying high-score stocks and shorting low-score stocks.

Formula

F-Score = Sum of 9 binary criteria (0 or 1 each) across Profitability (ROA, OCF, delta-ROA, accruals), Leverage (delta-Leverage, delta-Liquidity, dilution), and Efficiency (delta-Gross Margin, delta-Asset Turnover)

Why the F-Score Works: The Value Trap Problem

Not all cheap stocks are opportunities. Within the universe of low price-to-book stocks, Piotroski found a striking bifurcation: roughly half were genuinely undervalued businesses with improving fundamentals that subsequently outperformed, while the other half were cheap for legitimate reasons -- deteriorating businesses heading toward further losses or worse. Before the F-Score, these two groups were largely indistinguishable by price multiples alone.

The brilliance of the F-Score is its simplicity: nine binary yes/no questions, each answerable from public financial statements, that collectively capture whether the business is improving (cash generation increasing, leverage falling, efficiency rising) or deteriorating. No forecasting required, no DCF model needed. Pure accounting-based signal extraction from the information companies are already required to disclose.

Eliminate Distress with Altman Z-Score

Pair the Piotroski F-Score with the Altman Z-Score to eliminate both financially weak and financially distressed companies. A score of F >= 7 and Z > 2.99 is a powerful combination.

Learn About Altman Z-Score →

Frequently Asked Questions

What is the Piotroski F-Score and who created it?+
The Piotroski F-Score was developed by Stanford accounting professor Joseph Piotroski and published in his landmark 2000 paper 'Value Investing: The Use of Historical Financial Statement Information to Separate Winners from Losers.' Piotroski observed that low price-to-book stocks (classic value stocks) were a highly heterogeneous group: some were genuinely cheap, improving businesses while others were cheap for very good reason -- deteriorating fundamentals, financial distress, or outright manipulation. His F-Score system identified nine simple, binary accounting criteria that separated the winners from the losers within this universe, generating a 7.5% annual hedge return between high-score (8-9) and low-score (0-2) stocks.
What are the 9 Piotroski F-Score criteria?+
The 9 criteria fall into three groups. Profitability (4 criteria): (1) ROA positive (net income / total assets > 0), (2) Operating cash flow positive, (3) ROA improved year-over-year, (4) Accruals: operating cash flow > net income (cash earnings exceed reported earnings). Leverage/Liquidity (3 criteria): (5) Long-term leverage ratio decreased (debt-to-assets fell), (6) Current ratio improved, (7) No new shares issued in the past year (no dilution). Efficiency (2 criteria): (8) Gross profit margin improved year-over-year, (9) Asset turnover ratio improved year-over-year. Each criterion scores 1 if met, 0 if not. The total is the F-Score.
What F-Score should I look for?+
F-Score 8-9: Strong signal. The company is profitable, generating cash, improving on most dimensions, reducing leverage, and not diluting shareholders. Piotroski's original research showed the top-third (high-F-Score) vs bottom-third (low-F-Score) spread was approximately 23% per year in the low P/B universe. F-Score 6-7: Improving. Not all nine boxes checked but the trend is positive. Worth investigating. F-Score 0-2: Avoid or potential short. The company is failing most financial health tests simultaneously. In a value portfolio context, this is the profile of a value trap. F-Score 3-5: Mixed. Exercise judgment -- look at which criteria are passing and which are failing.
How do I use F-Score with other metrics to eliminate value traps?+
The most powerful application of the Piotroski F-Score is as part of a triple filter for classic value investing. Step 1: Screen for low valuation (P/B < 1.5 or low EV/EBIT). Step 2: Apply Altman Z-Score filter -- require Z > 2.99 (Safe Zone) to eliminate financially distressed companies. Step 3: Apply Piotroski F-Score -- require F >= 7 to ensure the company is financially strengthening, not deteriorating. Optional Step 4: Apply Beneish M-Score -- require M < -1.78 to eliminate potential earnings manipulators. The combination of low valuation + financial health + financial improvement + earnings quality removes the vast majority of value traps, leaving a much cleaner opportunity set of genuinely cheap, improving businesses.

Related Terms

Altman Z-Score

Multi-factor bankruptcy prediction model

Beneish M-Score

Earnings manipulation detection model

Accrual Ratio

Gap between reported earnings and cash flow

Return on Assets

Net income relative to total assets

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