This article examines the potential impact of the Covid-19 Lockdown on earnings manipulation and stock market sensitivity to earnings announcements. It also explores the effects of earnings manipulation after the COVID-19 outbreak on the share price sensitivity to the earnings disclosures. The study uses a quantitative method to analyze the financial data consisting of 87 firms listed on the Iraq Stock Exchange for the period from 2018 to 2020, which constitutes a total of (174 observations). We used Ohlson (1995) model to estimate financial market reaction and sensitivity to earnings manipulation fluctuations and accounting information. The results show that companies practice earnings manipulation to maintain earnings over a time series, which means a negative impact of earnings manipulation on all earnings measures' value relevance (EPS, BVS, and CFS). Accordingly, earnings manipulation negatively influences investor behavior in the financial market, based mainly on financial reporting. The value relevance of financial reports has also decreased because of the COVID-19 outbreak and related economic Lockdown. These results reflect a long-term adverse impact of earnings manipulation on investor behavior and financial statements reliability.