Résumé en anglais

The purpose of this paper is to study the effect of operational, market and accounting risks disclosures on investors' disagreements about French firms' value. The paper provides evidence on risks reporting efficiency in reducing investors' disagreements about the implication for firm's value of changes in underlying risks factors. Investors' disagreement is measured by trading volume. We work on the whole sample of French-listed firms and focus on those disclosing about their risks exposure. Using balanced panel data, we apply regression analyses for each risk factor changes on trading volume during 120 days before and after annual report release. The results show that only market risk reporting reduces disagreements about changes in underlying market rates or prices. This result is consistent with the theoretical efficiency of risks disclosures in improving value reporting. However, our findings indicate insignificant and weak effect of operational and accounting risks disclosures on investors' disagreements about changes in underlying risks factors. This evidence mitigates concerns about the usefulness of COB's (2002) operational and accounting risks disclosures requirements. Additional analysis reveals that risk disclosures reported in quantitative terms are more efficient than those reported in qualitative terms