I use a particular stock account for "fun money." At first I was going to withdraw yearly earnings?

... for that stock in December of each year to spend the following year. Instead, I decided to take money out each day during the year when the account rose above its beginning of the year value and then do that each time it rose above that value. On other days I hold. Over the course of a year it appears that my method produces a significantly higher amount of money than a withdrawal at the end of the year. I call the method "sell high, hold low". Is this a viable strategy? Is it used by others?