Portfolio correlation matrix is the powerful tool for your portfolio optimization. It allows optimal portfolio balancing be excluding from it closely correlated symbols. If you have several closely correlated symbols in portfolio, they similarly behave on market changes and do not add any stability to your portfolio. You must try to keep in portfolio only poorly related symbols. This generally increases portfolio stability because it will increase probability of some symbols growing when the others are on down slump.
It may eventually happen that your favorite symbol is not present in our Yahoo symbol lookup database, for example, due to a lag in database update. In this case, it is very easy to add symbol to lookup list, happen it is valid symbol existing on Yahoo Finance.
Go to “Home & Basics > Symbol” and simply enter proper symbol into search box. Then hit “Search” button. Symbol will be permanently added to lookup list and show up on chart.