Anytime you see C%3, C%7, or C%14 around it is just the average change percent for that stock in that timeline. C%3 is its average change percent for the previous 3 trading days. C%7 is for the last 7 previous days, and C%14 is for the last 14.
This is a Stock Wolf number to give you an idea of the stocks movements.
If a stock has a +% for any given period doesn't mean it will go up the following day, or any day. The same with -% averages, it doesn't mean the stock will go down.
These numbers are merely change percent averages for a given period.