The "Managing Portfolio" option includes the addition and removal of companies within Portfolios by clicking “add” and “remove”. 

The left-hand column contains companies which are not currently being monitored in the selected portfolio, and the right-hand column contains all companies that are being monitored in this selected portfolio. Companies can be added to a portfolio by selecting the company in the left-hand "Available Companies" list and clicking "Add". To remove a company from a portfolio click the tick-box next to the company in the right-hand column, then click on "Remove".