Stock Insights Academy · Model comparison
Piotroski F-Score vs. Altman Z″: What Each Measures
These scores are often grouped together, but they answer different questions. Piotroski evaluates whether financial fundamentals are improving and internally consistent; Stock Insights uses Altman Z-double-prime (Z″) to screen financial-distress risk in eligible non-financial operating companies.
Awards nine binary signals across profitability, leverage/liquidity and operating efficiency.
Best suited to
- Fundamental quality screening
- Value-stock research
- Comparing year-over-year direction
Main limitation: Binary signals discard magnitude and can oversimplify borderline changes.
Uses Z″ = 6.56X₁ + 3.26X₂ + 6.72X₃ + 1.05X₄, based on working capital, retained earnings, EBIT and book equity relative to the required balance-sheet denominators.
Best suited to
- Credit and solvency screening
- Non-financial operating companies
- Identifying balance-sheet warning signs
Main limitation: It is unavailable for financial businesses and whenever a required reported statement input is missing.
Key differences
| Criterion | Piotroski F-Score | Altman Z″ | Decision insight |
|---|---|---|---|
| Primary question | Are fundamentals improving? | How elevated is financial-distress risk? | Quality momentum and distress risk are related but not identical. |
| Output | Integer from 0 to 9 | Continuous Z″ score | Do not compare the raw numbers directly. |
| Formula structure | Nine pass/fail accounting signals | 6.56X₁ + 3.26X₂ + 6.72X₃ + 1.05X₄ | F-Score counts signals; Z″ weights four reported-statement ratios. |
| Time dimension | Uses current and prior-year changes | Uses current reported balance-sheet and EBIT relationships | F-Score emphasizes direction; Z″ emphasizes current financial condition. |
| Interpretation | Higher scores indicate more positive signals | <1.1 distress; 1.1–<2.6 grey; ≥2.6 above grey | Z″ bands are screening zones, not bankruptcy probabilities or guarantees of safety. |
| Best use | Screen then investigate | Distress-risk flag then investigate | Neither score replaces financial-statement analysis. |
Improving operations with a still-weak balance sheet
A cyclical operating company may earn a high F-Score as profitability and cash generation recover from a trough.
The same company can retain a weak Z″ because accumulated losses, working-capital pressure or leverage still leave little balance-sheet protection.
Together, the scores describe a recovery with meaningful residual solvency risk—more useful than forcing one score to answer both questions.
Practical verdict
Which approach should you use?
Use Piotroski to assess the direction and quality of fundamentals. Use Altman Z″ to flag financial distress when the company and reported inputs are eligible. When both are available, the combination is stronger because improving fundamentals do not necessarily imply low distress risk, and a high Z″ does not necessarily imply improving economics.
Related calculators and guides
Frequently asked questions
Is a high F-Score the same as a high Altman Z″?
No. A high F-Score indicates more positive fundamental signals, while a higher Z″ generally indicates lower modeled financial-distress risk within the model's eligible company set.
Can a company score well on one and poorly on the other?
Yes. Improving profit and cash flow can lift F-Score before retained earnings, working capital or leverage recover enough to improve Z″.
What Altman formula does Stock Insights use?
Stock Insights uses Z″ = 6.56X₁ + 3.26X₂ + 6.72X₃ + 1.05X₄. X₁ is working capital / total assets, X₂ retained earnings / total assets, X₃ EBIT / total assets and X₄ book equity / total liabilities.
What are the Altman Z″ thresholds?
Scores below 1.1 are in the distress zone, 1.1 to below 2.6 are in the grey zone and scores of 2.6 or more are above the grey zone.
Does Altman Z″ work for banks or insurers?
Stock Insights does not apply Z″ to financial businesses such as banks and insurers because their balance sheets, leverage and regulatory capital structures are fundamentally different.
Are the scores buy signals?
No. They are screening and diagnostic tools. Valuation, business quality, accounting context and forward-looking risks still matter.