Add this bit of information in your tables.
I believe it is important for a user to know the date when any given stock that appears today on any of your prebuilt search screens was first added to this screen. This would help a user to know how old in the tooth that trend is for that particular stock and make his decision whether or not to invest in that stock. At present, it seems there is no way of getting this info. You may consider adding a column in the tables to exhibit this date for each stock.