Hi all,

I have a panel dataset of companies with trading days for the period from 2010 until 2020. However, i will need to drop the company who has more than 50% of missing values or the return is 0 Return in one of the trading years (2010 or 2011 or...).

As i see I need to generate a trading days for USA for this period (2010- june2020) and than match the days of trading of each company, so if the return of the company is missing or the return is equal to 0, that company to be drooped from the sample. However, i do not know how to write this command.Attached i am sending a sample.

Knowing the expertise that you have, I was hoping that you could help me in solving this problem.

Sincerely,