In 2020, due to macroeconomic changes such as oil prices and the COVID-19 pandemic, the Circuit Breaker (CB) was activated in the Brazilian market to contain market volatility. Several sectors were negatively affected; however, the agribusiness sector recorded an increase in the volume of commodity exports. Thus, it is relevant to evaluate the performance of companies associated with the Brazilian agroindustrial sector, since it is a cross-cutting sector that involves different production chains in the country, in addition to identifying the behavior of investors in this period not only of insecurity and risk, but also of increased investments. Therefore, the objective of this study is to analyze the differences in stock returns in 2020, considering the companies in the agro-fishery sector that have published explanatory notes on COVID-19 in 2020. Monthly and daily return data of four co...