Chapter 3: Effects of the COVID-19 Pandemic on the Top Seven Mexican Exporting Companies^*

The purpose of this research is to reveal the behaviour of the main Mexican exporting companies during the 2018-2020 period, which covers part of the COVID-19 pandemic phase. The results indicate that it is not viable to invest in this type of companies for the time being, and this is shown empirically through the traditional Markowitz investment portfolio selection methodology and its extension through the Sharpe model.