What Is the Piotroski F-Score? A Quality Checklist

The Piotroski F-Score is a nine-point checklist developed by accounting professor Joseph Piotroski that evaluates a company's financial strength using publicly available accounting data. Each of nine binary tests earns a score of 0 or 1, producing a total score from 0 (worst) to 9 (best). It was originally designed to separate strong value stocks from weak ones — and research has shown it works remarkably well as a simple quality filter.

The Nine Signals

Profitability (4 signals)

1. Positive net income in the current year (1 point). The most basic profitability test — is the company making money? 2. Positive operating cash flow in the current year (1 point). Cash flow confirms that earnings are backed by real money, not just accounting entries. 3. ROA (return on assets) higher this year than last (1 point). Improving ROA means the company is using its assets more efficiently. 4. Operating cash flow exceeding net income (1 point). This "accrual" test checks whether earnings quality is high — cash flow should match or exceed reported income.

Leverage and Liquidity (3 signals)

5. Lower ratio of long-term debt to assets than the prior year (1 point). The company is reducing its leverage — strengthening its balance sheet. 6. Higher current ratio than the prior year (1 point). Improved short-term liquidity means the company can more easily meet its near-term obligations. 7. No new shares issued during the year (1 point). Companies that avoid diluting shareholders signal financial self-sufficiency — they don't need to raise equity capital.

Operating Efficiency (2 signals)

8. Higher gross margin than the prior year (1 point). Expanding gross margins indicate improving pricing power or cost control — the company is getting better at converting revenue into gross profit. 9. Higher asset turnover (revenue ÷ total assets) than the prior year (1 point). Improved asset turnover means the company is generating more revenue per dollar of assets — becoming more efficient.

How to Use the F-Score

In our analysis, a score of 8-9 indicates a financially strong company — profitable, generating cash, deleveraging, and becoming more efficient. These are the characteristics that quality investors seek. A score of 0-2 indicates financial weakness across multiple dimensions — a company that's losing money, burning cash, adding debt, and becoming less efficient.

Piotroski's original research showed that buying high-F-Score stocks and shorting low-F-Score stocks among value stocks (low price-to-book) generated significant excess returns. The F-Score is particularly powerful when applied to cheap stocks — it separates the cheap-and-improving (genuine value) from the cheap-and-deteriorating (value traps).

F-Score Strengths

Simplicity is the F-Score's greatest strength. Nine binary tests using readily available accounting data — anyone can calculate it. No subjective judgment, no complex modeling, no estimates of future growth. It's purely backward-looking and purely quantitative, which means it's replicable and free of bias.

It's also well-validated. Multiple academic studies across different time periods and international markets have confirmed that high-F-Score stocks outperform low-F-Score stocks. The signal is robust and persistent.

F-Score Limitations

The F-Score uses only one year of data and looks only at year-over-year changes. A company with 25% ROIC that dipped from 28% last year scores the same as a company with 6% ROIC that dipped from 8%. The level of quality — which is arguably more important than the direction — isn't captured.

It doesn't assess competitive position, moat, management quality, or valuation — all of which are central to a complete quality investing framework. A company can score 9/9 on the F-Score while facing a deteriorating competitive position that the accounting signals haven't yet reflected.

The F-Score is best used as a screening tool or supplementary check — not as a standalone investment system. It answers the question "is this company's financial health improving or deteriorating?" but not "is this a great business worth owning for a decade?"

F-Score and MoatScope's Quality Score

MoatScope's Quality Score is conceptually similar in spirit — both aim to quantify business quality using financial data — but much more comprehensive. Where the F-Score uses 9 binary signals from one year, MoatScope's seven-pillar framework evaluates returns on capital, margin strength, earnings consistency, financial health, durability, management quality, and competitive position using multi-year data and AI moat analysis.

Think of the F-Score as a useful first pass and MoatScope's Quality Score as the deeper, multi-dimensional assessment. Both are trying to answer the same fundamental question: is this a high-quality business? They just approach it at different levels of depth and sophistication.