Lev and Thiagarajan (1993) document that financial signals have predictive power in explaining contemporaneous stock returns of U.S. firms and Abarbanell and Bushee (1998) show that forming investment portfolios by longing high-score stocks and shorting low-score stocks based on fundamental signals suggested by Lev and Thiagarajan (1993) yields significant positive returns. In addition, empirical results in Piotroski (2000) and Mohanram (2005) suggest that a portfolio with higher composite scores earn higher future returns for high and low book-to-market (BM) firms in U.S. markets, respectively. The composite score in Piotroski (2000) is constructed based traditional financial measures in three aspects:
profitability, leverage and liquidity, and operating efficiency while the composite score in Mohanram (2005) is constructed based on traditional profitability measures as well as
growth-oriented measures