This paper aims at studying the market response surrounding profit warnings as well as annual earnings announcements. Relatively few academic researches have investigated these issues. Our empirical survey based on an event study, points out a strong negative residual stock returns around profit warning announcements corresponding to bad news as well as abnormally high volatility and trading volumes whereas we observe positive abnormal returns at the date of earnings announcements for companies having previously released a profit warning in the market. Our results testify that those both disclosures convey an informative content for investors and market participants. Those findings may arise from earnings management policies because mangers are more likely to postpone good news disclosures and announce bad news as early as possible to satisfy investors' informative requirements.