Come calcolare il Piotroski F-Score: indicatore composito 9 punti binari measuring financial strength quality value stocks per value investing screening complement Altman Z-Score bankruptcy prediction. Formulato da Joseph D. Piotroski (USA 1968-) University Chicago Booth School Business 2000 paper "Value Investing: The Use of Historical Financial Statement Information to Separate Winners from Losers" Journal of Accounting Research 38:1-41 backtested empirical outperformance 1976-1996 low book-to-market value stocks. 9 binary tests ciascun valore 0 o 1: Profitability (4 punti): (

• Net Income > 0 positive; (
• Return on Assets ROA = NI/TA > 0 positive; (
• Operating Cash Flow OCF > 0 positive; (
• OCF > Net Income (quality earnings, no aggressive accounting accruals). Leverage/Liquidity (3 punti): (
• Long Term Debt / Total Assets decreased year-over-year YoY (deleveraging healthy); (
• Current Ratio CA/CL increased YoY (liquidity improved); (
• No new common shares issued YoY (no dilution). Operating Efficiency (2 punti): (
• Gross Margin increased YoY (pricing power); (
• Asset Turnover Sales/TA increased YoY (efficiency). Total F-Score 0-9. Classification: F-Score = 8-9 Excellent strong buy candidate value stock superior financial strength; 7 Good buy; 4-6 Average hold monitoring; 0-3 Poor avoid high risk. Backtested 1976-1996 portfolio low book-to-market B/M stocks F-Score>=8 outperformed market 7.5% annualized vs F-Score<=2 underperform. Strumento essenziale per: value investing Italia equity research Bocconi Milano CESMER Centro Studi Management Ricerca; ricerca finanziaria Italia università: Sapienza Roma DIET, Bologna alma mater 1088 prima Europa Statistica DEMS, Pisa SNS Mathematics, LUISS Roma Carli, Cattolica Milano CESPLA; investitori istituzionali Italia Generali Trieste Mediolanum Basiglio UnipolSai Bologna Poste Vita Roma; fondi pensione COVIP Commissione Vigilanza Fondi Pensione Roma; analisti finanziari Italia AIAF Associazione Italiana Analisti Finanziari Milano 1971 fondata 4500 membri

Formula Piotroski F-Score

9 binary tests struttura: F-Score = sum 9 indicators ciascun 0 (fail) o 1 (pass). Range totale 0-9. Categorie: Profitability 4 tests (NI, ROA, OCF, OCF vs NI), Leverage/Liquidity 3 tests (LTDebt, CurrentRatio, Shares), Operating Efficiency 2 tests (GrossMargin, AssetTurnover). Tutti tests YoY year-over-year comparison anno corrente vs anno precedente. Equal weighting tutti tests, no rebalancing coefficients (vs Altman MDA discriminant).

Profitability tests (4 punti): (

• Net Income > 0 positive operating profit current period; (
• ROA = Net Income / Average Total Assets > 0 (avg = (TA+TA_prev)/2); (
• Operating Cash Flow OCF > 0 positive cash from operations after working capital adjustments; (
• Earnings Quality: OCF > Net Income (cash earnings exceed accrual earnings, no aggressive accounting Worldcom Enron-style fraud)

Leverage/Liquidity tests (3 punti): (

• ΔLong Term Debt: LongTermDebt/TotalAssets ratio decreased YoY (deleveraging healthy reducing financial risk); (
• ΔCurrent Ratio: CurrentAssets/CurrentLiabilities increased YoY (improved short-term liquidity working capital management); (
• ΔShares Outstanding: no new common shares issued YoY (no equity dilution shareholders ownership preserved)

Operating Efficiency tests (2 punti): (8) ΔGross Margin: (Revenue - COGS) / Revenue ratio increased YoY (pricing power competitive advantage market position); (9) ΔAsset Turnover: Sales/Average Total Assets increased YoY (efficiency assets generating revenue).

Backtest historical performance: Piotroski 2000 paper sample 14043 firms NYSE AMEX NASDAQ low book-to-market B/M ratio (cheap value stocks) 1976-1996, F-Score >= 8 portfolio outperformed average value stocks 7.5% annualized return; F-Score <= 2 portfolio underperformed -7.5% spread 13-15% top-bottom. Foundation modern value investing systematic screening, integration with Magic Formula Greenblatt 2005 Quality Investing Buffett-style.

Storia e contesto

Joseph D. Piotroski (USA 1968-) Stanford University Graduate School Business GSB Professor Accounting 2003-current, prior University Chicago Booth School Business Doctoral Office 2000-2003. PhD University Michigan 2000 thesis "Value Investing: The Use of Historical Financial Statement Information to Separate Winners from Losers" published Journal of Accounting Research 38:1-41 supplement 2000 (Studies on Accounting Information and the Economics of the Firm). Empirical methodology: 14043 firms NYSE AMEX NASDAQ low B/M ratio cheap value stocks 1976-1996 sample, 9 financial signal tests assigned binary 0/1 score, portfolio quintile 5 high F-Score >= 8 outperform market 7.5% annualized, quintile 1 low F-Score <= 2 underperform -7.5% relative spread 13-15% Long-Short strategy alpha. Subsequent papers: 2008 "Identifying Expectation Errors in Value/Glamour Strategies" Review of Financial Studies extended global markets evidence; 2018 "Effective Tax Planning" Tax Notes magazine practitioner application. Stanford GSB profile: Trione Visiting Professor 2003+, Joel Stern Professor Accounting 2010+. Joel Greenblatt (USA 1957-) Magic Formula 'Little Book that Beats the Market' 2005 Wiley simple two-factor formula ROIC + Earnings Yield ranking complementary Piotroski quality. Warren Buffett (USA 1930-) Berkshire Hathaway Inc Omaha NE famous value investor following Benjamin Graham 1934 'Security Analysis' McGraw-Hill foundation value investing intrinsic value moat economic advantage.

Italia ricerca finance: Bocconi Università Commerciale Luigi Bocconi Milano 1902 fondata 14000 students top business school Italy Department Finance Stefano Caselli decano; SDA Bocconi MBA Milano top European business school; LUISS Guido Carli Roma 1974 fondata 9000 students; Cattolica del Sacro Cuore Milano-Roma 1921 fondata; CUOA Vicenza Business School. Italia investitori istituzionali: Generali Group Trieste 1831 fondata 75000 employees largest Italian insurer global top 10; Mediolanum Banca Basiglio Milano 1982 fondata Doris family insurance bank conglomerate; UnipolSai Bologna 1962 fondata insurance multi-line; Poste Vita Roma 1959 postal insurance subsidiary Poste Italiane state-owned; Banca d'Italia Roma supervisione vigilanza credito; CONSOB Roma supervisione mercati finanziari; Borsa Italiana Milano FTSE MIB 40 stocks. AIAF Associazione Italiana Analisti Finanziari Milano 1971 fondata 4500 membri professional financial analysts CFA equivalent. Italia famous value investors: Davide Serra Algebris Investments London Italy 2006 fondato; Giovanni Tamburi Tamburi Investment Partners TIP Milano 1992 fondato. Italia research: Universita Bocconi CESMER Centro Studi Management Ricerca; Universita Bologna DEMS Statistica; Sapienza Roma DIET Mathematica Statistica; LUISS Roma; Cattolica Milano CESPLA; Universita Pisa SNS Mathematics. USA value investors famous practitioners following Piotroski: Tweedy Browne Co LLC NYC 1920 founded value firm;

Royce & Associates NYC 1972 small cap value; Brandes Investment Partners San Diego CA 1974 international value. USA value investing universities: NYU Stern Greenwich Village Manhattan Edward Altman 1968 Z-Score; Wharton Penn Philadelphia PA 1881 oldest US business school 50000 alumni; Harvard Business School Boston MA 1908; Booth Chicago IL 1898 Joel Stern; Columbia Graduate School Business NY 1916 Benjamin Graham 1928-1956 'Security Analysis' father value investing; MIT Sloan Cambridge MA 1914; Stanford Graduate School Business GSB Palo Alto CA 1925 Piotroski 2003+. Famous USA value investors: Warren Buffett Berkshire Hathaway Inc Omaha NE; Charlie Munger 1924-2023 Buffett partner; Seth Klarman Baupost Group Boston MA; Howard Marks Oaktree Capital LA CA distressed debt; Bruce Berkowitz Fairholme Funds; Mohnish Pabrai Pabrai Investment Funds Irvine CA Indian-American Buffett follower; Tom Russo Gardner Russo & Quinn Lancaster PA. USA stock market: NYSE NYC; NASDAQ Times Square NYC; S&P 500 Russell 2000 Wilshire 5000 indexes; CBOE Chicago Board Options Exchange Chicago IL. Software financial analysis: Bloomberg Terminal NYC subscription $24000/year financial data; Reuters Refinitiv Thomson; FactSet; Capital IQ S&P; Morningstar Chicago IL fund ratings; Stockopedia London UK F-Score automatic; Gurufocus Plano TX F-Score automatic; SimplyWall.St Sydney Australia. Software open source: SEC Edgar Online Filings free public; Yahoo Finance free quotes; Google Finance free;

Wisesheets Excel.

Tabella F-Score classifications

• F-Score 8-9 Excellent: Strong Buy value stock candidate, top quintile financial strength
• F-Score 7 Good: Buy financial health solid
• F-Score 4-6 Average: Hold monitor trend, mixed signals
• F-Score 0-3 Poor: Avoid high financial risk
• Test 1 NI>0: positive net income current period
• Test 2 ROA>0: positive return on assets
• Test 3 OCF>0: positive operating cash flow
• Test 4 OCF>NI: cash earnings exceed accrual quality
• Test 5 LTDebt decreased: deleveraging healthy
• Test 6 Current Ratio increased: liquidity improved
• Test 7 No new shares: no equity dilution
• Test 8 Gross Margin increased: pricing power
• Test 9 Asset Turnover increased: efficiency
• Backtest 1976-1996: F-Score>=8 outperform 7.5% annualized
• Long-Short spread: 13-15% Long F>=8 vs Short F<=2
• Sample size: 14043 firms NYSE AMEX NASDAQ
• Filter: low book-to-market B/M ratio cheap value
• Joel Greenblatt Magic Formula: ROIC + EY 2005
• Warren Buffett: Berkshire Hathaway Omaha NE
• Benjamin Graham: Columbia 1928-1956 father value
• USA value investors: Tweedy Browne, Royce, Brandes
• Italia AIAF: 1971 fondata 4500 analisti finanziari
• Italia Bocconi: 1902 14000 students top business
• Italia LUISS Roma: 1974 9000 students
• Italia Generali: 1831 Trieste 75000 employees
• Italia Mediolanum: 1982 Basiglio Doris family

Esempi numerici dettagliati

Esempio 1 - Excellent F-Score 9 azienda solida. NI=$100M (positive), ROA=100/975=10.3% positive, OCF=$150M positive > NI, LTDebt $200M 2.05 increased, shares 100 = 100 no new, GM 40% > 35%, AT 1.5 > 1.47 increased. F-Score = 1+1+1+1+1+1+1+1+1 = 9. Classification Excellent strong buy. Italia: typical FTSE MIB blue chip Borsa Italiana Milano top-tier value stock. Backtest historical 1976-1996 portfolio F=9 outperform mercato 7.5% annualized.

Esempio 2 - Average F-Score 4 mid-tier. NI=$50M positive (1), ROA=50/975=5.1% positive (1), OCF=$40M positive (1), OCF $280M increased fail (0), CR=1.6 vs 1.65 decreased fail (0), 105 shares > 100 dilution fail (0), GM 30% < 32% decreased fail (0), AT 1.2 < 1.37 decreased fail (0). F-Score = 1+1+1+0+0+0+0+0+0 = 3. Classification Poor avoid. Italia mid-cap struggling small-medium enterprise mixed financials.

Esempio 3 - Poor F-Score 0 distressed. NI=-$50M loss (0), ROA=-50/1050=-4.8% negative (0), OCF=-$30M negative (0), OCF<NI(both negative but OCF $450M increased (0), CR=0.86 100 dilution (0), GM 20% < 25% (0), AT 0.8 < 0.82 (0). F-Score = 0. Distressed company high risk Avoid. Italia: pre-bankruptcy Tribunale Concorsuale procedura concordato preventivo CCII Decreto Legislativo 14/2019.

Esempio 4 - Apple AAPL 2023 retrospective F-Score. Apple Inc Cupertino CA 1976 founded Steve Jobs Steve Wozniak. Net Income $97B positive (1), ROA = 97/350 = 27.7% positive (1), OCF $111B positive (1), OCF $111B > $97B NI quality (1), LTDebt $98B vs $98B unchanged but ratio TA decreased (1), Current Ratio 0.99 vs 0.88 increased (1), shares 15.7B vs 15.9B buybacks no dilution (1), Gross Margin 44.1% vs 43.3% increased (1), Asset Turnover 1.09 vs 1.04 increased (1). F-Score = 9 Excellent! Apple retrospective bull market top-tier value stock high quality.

Esempio 5 - Compare Piotroski vs Altman Z-Score. Stesso azienda dataset esempi 1-3: Esempio 1 Excellent F=9 corresponds Altman Z>2.99 Safe Zone bankruptcy <0.5%; Esempio 2 Average F=3 corresponds Altman Z 1.81-2.99 Grey Zone monitoring; Esempio 3 Poor F=0 corresponds Altman Z25% probability. Piotroski quality forward-looking value stocks; Altman bankruptcy backward-looking solvency. Complementary tools value investing screening: Piotroski F>=7 + Altman Z>2.99 = high-quality safe value stock candidate.

Limiti e considerazioni

1. Equal weighting 9 tests: not all tests equally predictive empirical, profitability tests weight stronger statistical correlations.
2. YoY comparison limited single year: trend 3-5 anni più robust avoid one-time accounting effects.
3. No industry adjustment: gross margin asset turnover vary by industry technology vs retail vs utilities, sector-specific benchmarks better.
4. USA-specific original 1976-1996: emerging markets may have different financial reporting standards IFRS vs GAAP differences.
5. Banks insurance financial: Piotroski not designed for financial sector, alternative metrics needed.
6. Small companies micro-cap data quality: financial statements unreliable small caps, F-Score less reliable.
7. Stock buybacks distort: large buybacks reduce shares outstanding favorably trigger Test 7 = pass even if shareholder dilution overall.
8. Aggressive accounting: revenue recognition fraud (Enron WorldCom) inflate NI ROA pass tests false positive.
9. Cyclical industries: airlines automotive construction high beta volatile margins F-Score volatile year-over-year.
10. Modern adjustments: Piotroski 2008 paper extended global markets, but no formal updates 9-test methodology since 2000.

Errori comuni

1. Confondere F-Score (9-point quality) con Z-Score (continuous bankruptcy distance): different metrics complementary use.
2. Trascurare YoY comparison: F-Score requires 2 years financial data, single year insufficient.
3. Pretendere Piotroski applicabile banks: alternative metrics needed financial sector.
4. Confondere OCF > NI quality test: positive both required, OCF must EXCEED NI for accrual quality.
5. Trascurare average TA denominator ROA: (TA+TA_prev)/2 NOT just current TA.
6. Confondere current ratio improvement: CR increase pass even if both years > 1.0 healthy.
7. JavaScript Math precision: ratio comparisons floating point edge cases very close values.
8. Pretendere F=9 guarantee outperform: backtest evidence statistical significance not individual stock guarantee.
9. Trascurare context industry sector: relative comparison sector peers more meaningful.
10. Confondere F-Score (Piotroski 2000) con F-test (Fisher statistical): completely different concepts.

Applicazioni numerate

1. Italia value investing: AIAF Associazione Italiana Analisti Finanziari Milano 1971 fondata 4500 membri professional financial analysts CFA equivalent.
2. Italia università finance: Bocconi Milano 1902 14000 students top business school Italy Department Finance Stefano Caselli decano; SDA Bocconi MBA top European; LUISS Guido Carli Roma 1974 9000 students.
3. Italia investitori istituzionali: Generali Group Trieste 1831 fondata 75000 employees largest Italian insurer; Mediolanum Banca Basiglio Milano 1982 Doris family; UnipolSai Bologna 1962; Poste Vita Roma 1959.
4. Italia famous value investors: Davide Serra Algebris Investments London Italy 2006 fondato; Giovanni Tamburi Tamburi Investment Partners TIP Milano 1992 fondato.
5. USA value investing universities: Stanford GSB Palo Alto CA 1925 Piotroski 2003+; Booth Chicago IL 1898; Columbia Graduate School Business NY 1916 Benjamin Graham 1928-1956 father value.
6. USA famous value investors: Warren Buffett Berkshire Hathaway Omaha NE; Charlie Munger 1924-2023 Buffett partner; Seth Klarman Baupost Boston MA; Howard Marks Oaktree Capital LA CA distressed debt; Mohnish Pabrai Indian-American Buffett follower.
7. USA value investing firms: Tweedy Browne NYC 1920 founded; Royce & Associates NYC 1972 small cap value; Brandes Investment Partners San Diego CA 1974 international.
8. USA stock market: NYSE NYC; NASDAQ Times Square NYC; S&P 500 Russell 2000 Wilshire 5000 indexes; CBOE Chicago Board Options Exchange Chicago IL.
9. Software financial: Bloomberg Terminal NYC $24000/year; FactSet; Morningstar Chicago IL fund ratings; Stockopedia London UK F-Score automatic; Gurufocus Plano TX.
10. Joel Greenblatt Magic Formula: 'Little Book that Beats the Market' 2005 ROIC + EY simple two-factor complementary Piotroski quality.

Per supporto

Per domande tecniche: info@calcoi.com. Strumento didattico value investing. Per applicazioni Piotroski JD 2000 'Value Investing: The Use of Historical Financial Statement Information to Separate Winners from Losers' Journal of Accounting Research 38:1-41, Greenblatt J 2005 'The Little Book That Beats the Market' Wiley, Graham B Dodd D 1934 'Security Analysis' McGraw-Hill foundation value investing, Buffett W 1956+ Berkshire Hathaway letters shareholders.

Aggiornato a luglio 2026