Direct Answer
The Piotroski F-Score, developed by accounting professor Joseph Piotroski in 2000, is a 9-point checklist spanning profitability, leverage/liquidity, and operating efficiency signals used to screen for financially improving companies, particularly among low price-to-book value stocks. A company earns one point for each of the nine signals it passes, so scores range from 0 to 9 - a score of 8 or 9 commonly indicates strong fundamental improvement, while 0 to 2 commonly indicates deterioration.
Key Takeaways
- The F-Score awards one point per signal across nine year-over-year tests, for a total range of 0 to 9.
- The nine signals fall into three groups: profitability (four signals), leverage and liquidity (three signals), and operating efficiency (two signals).
- Piotroski designed and tested the score specifically among low price-to-book value stocks, where cheap valuation alone doesn't reveal whether the underlying business is improving or deteriorating.
- Higher scores (commonly 8-9) suggest broad-based fundamental improvement; lower scores (commonly 0-2) suggest broad-based deterioration.
- Every input comes from figures already reported on the income statement, balance sheet, and cash flow statement - no external data or market price is required to compute it.
- The F-Score measures the direction and breadth of recent change, not valuation, quality, or a standalone buy signal.
What Are the Nine Piotroski F-Score Signals?
Each signal compares the most recent fiscal year against the prior fiscal year and is scored as a binary pass (1 point) or fail (0 points). The nine signals are grouped into three categories:
| Category | Signal | Point earned when... |
|---|---|---|
| Profitability | Net income | Net income is positive. |
| Operating cash flow | Operating cash flow is positive. | |
| Change in return on assets (ROA) | ROA is higher than the prior year. | |
| Accruals (quality of earnings) | Operating cash flow exceeds net income. | |
| Leverage / Liquidity | Change in long-term debt ratio | Long-term debt relative to assets is lower than the prior year. |
| Change in current ratio | The current ratio (current assets ÷ current liabilities) is higher than the prior year. | |
| Shares outstanding | No new common shares were issued during the year. | |
| Operating Efficiency | Change in gross margin | Gross margin is higher than the prior year. |
| Change in asset turnover | Asset turnover (revenue ÷ total assets) is higher than the prior year. |
Summing the nine pass/fail results produces the F-Score. The logic behind each group is straightforward: the profitability signals check whether the core business is actually earning and generating cash, the leverage and liquidity signals check whether the balance sheet is getting sturdier rather than more strained, and the operating efficiency signals check whether the company is extracting more from its existing sales and asset base rather than relying on external factors.
Why Does the F-Score Focus on Low Price-to-Book Stocks?
A low price-to-book ratio can mean two very different things. It can mean the market is undervaluing a fundamentally sound business - a classic value opportunity. Or it can mean the market has correctly priced a business that is genuinely deteriorating, and the low valuation is simply reflecting that decline in advance. Price-to-book alone can't distinguish between the two; it only tells you the stock is statistically cheap relative to book value, not why.
Piotroski's research targeted exactly this ambiguity: within a universe of low price-to-book stocks, the F-Score sorts companies by the direction of their recent fundamentals rather than by price. A high-scoring low price-to-book stock has passed most of the nine tests for improving profitability, a strengthening balance sheet, and better operating efficiency - suggesting the cheap valuation may not yet reflect that improvement. A low-scoring low price-to-book stock has failed most of those same tests, suggesting the cheap valuation may be justified rather than mispriced. In both cases, the F-Score is a screen for separating candidates worth deeper research from those the accounting data itself is warning about, applied within the specific low price-to-book universe it was built and tested on. See the Swoopr Glossary for a plain-language definition of price-to-book and other value-investing terms referenced here.
Worked Hypothetical Example: Scoring a Company
A hypothetical low price-to-book company reports the following year-over-year changes:
| Signal | Reported change | Point? |
|---|---|---|
| Net income | Positive ($12 million) | 1 |
| Operating cash flow | Positive ($18 million) | 1 |
| Change in ROA | Rose from 4.1% to 5.0% | 1 |
| Accruals | Operating cash flow ($18M) exceeds net income ($12M) | 1 |
| Change in long-term debt ratio | Fell from 28% to 24% of assets | 1 |
| Change in current ratio | Fell from 1.6 to 1.4 | 0 |
| Shares outstanding | No new shares issued | 1 |
| Change in gross margin | Rose from 31% to 33% | 1 |
| Change in asset turnover | Fell from 0.95× to 0.90× | 0 |
Summing the point column gives an F-Score of 7 out of 9. This hypothetical company passed both accrual-quality profitability tests and improved its debt ratio, gross margin, and net income, while failing on current ratio and asset turnover. A score of 7 sits below the 8-9 range commonly read as the strongest improvement signal, but well above the 0-2 range commonly read as deterioration - it would typically prompt a closer look at why liquidity and asset turnover moved the wrong way even as profitability and leverage improved, rather than being treated as an automatic pass or fail on its own.
Worked hypothetical example: F-Score
Good
- Profitability4 / 4
- Leverage and liquidity2 / 3
- Operating efficiency1 / 2
- This example is hypothetical - all figures are illustrative, not drawn from a real company's filings.
- A single year-over-year comparison does not capture a full business cycle.
- Always verify each input against the company's actual 10-K or 10-Q figures before relying on a computed score.
Limitations and Common Mistakes
The F-Score treats every signal equally - one point is one point whether it comes from a large jump in ROA or a razor-thin improvement in the current ratio. That equal weighting means a score can look identical for a company with broad, meaningful improvement and one that barely cleared several thresholds by a small margin. Reading which specific signals passed or failed, not just the total, is usually more informative than the number alone.
The score is also purely backward-looking and mechanical: it compares this year's reported figures to last year's and says nothing about competitive position, industry conditions, management quality, or valuation beyond the price-to-book ratio used to build the initial screening universe. A common mistake is applying the F-Score outside that low price-to-book context - for example, to a high-growth or high price-to-book company where a signal like "no new shares issued" can penalize a healthy, well-timed capital raise rather than flag a warning sign. Accounting figures can also be restated or contain one-time items that distort a single year's comparison, so a score should be treated as a starting screen for further research, not a finished conclusion.
Frequently Asked Questions
What is a good Piotroski F-Score?
A score of 8 or 9 is commonly treated as a strong signal of fundamental improvement, since the company passed nearly every profitability, leverage/liquidity, and efficiency test in the checklist. A score of 0 to 2 commonly signals deterioration across most of those same tests. Scores in the middle are more ambiguous and typically call for closer reading of which specific signals passed or failed rather than treating the total alone as a verdict.
What are the nine Piotroski F-Score signals?
The nine signals span three categories. Profitability includes positive net income, positive operating cash flow, improving return on assets, and operating cash flow exceeding net income. Leverage and liquidity include a lower long-term debt ratio, an improving current ratio, and no new shares issued during the period. Operating efficiency includes an improving gross margin and improving asset turnover. Each passed signal earns one point, for a maximum of nine.
Does the Piotroski F-Score work on all stocks or only value stocks?
Joseph Piotroski designed and tested the F-Score specifically among low price-to-book value stocks, where his original research found it most effective at separating financially improving companies from deteriorating ones. Applying it to high-growth or high price-to-book companies is less established, since several signals, such as no new share issuance, can flag capital raises that are normal for a fast-growing business rather than a warning sign.
Is a high Piotroski F-Score a buy signal by itself?
No. The F-Score is a screening tool that measures the direction and breadth of recent fundamental change, not a valuation, a price target, or a complete investment thesis. A high score means a company passed most of the nine year-over-year tests; it says nothing about the current share price, the durability of the improvement, industry conditions, or qualitative factors like competitive position or management quality.
Why was the score designed specifically for value stocks?
The original research addressed the observation that value portfolios contain both mispriced companies and genuinely deteriorating ones, and sought a way to separate them using accounting signals. The score was tested on a value-sorted universe. Applying it to a broad universe or to growth stocks extends it beyond its intended context, where its documented results do not apply.
What do the nine signals measure in general terms?
They cover profitability, including positive returns and cash generation, leverage and liquidity trends, and operating efficiency trends including margin and asset turnover. Each contributes one point when the condition is met. The construction deliberately uses simple binary tests rather than weighted continuous measures, which makes it reproducible from any standard dataset.
How stable is a company's score across periods?
Several signals compare against the prior year, so the score moves as year-over-year changes reverse, which makes it more volatile than a level-based measure. A company can score highly in a recovery year and poorly the following year without deteriorating. This is why the score is used as a periodic ranking rather than as a stable characteristic.
Does the score work outside the market and period it was developed on?
Subsequent research has applied it to other markets and later periods with results that vary in strength and are generally weaker than the original study. This is the usual pattern for published findings. It supports treating the score as a screening aid whose historical performance figures should not be assumed to describe current conditions.
How should the score be combined with a valuation filter?
The original application sorted a value universe by the score and compared the high-scoring group against the low-scoring one, so the valuation filter comes first and the score separates within it. Applying the score first and then filtering on valuation reverses the construction. The sequence matters because the score was calibrated on an already value-sorted population.