In mid-2009, Morningstar introduced what it calls "moat trend ratings." Moat trend ratings can be either positive or negative. A positive moat trend indicates that a company's competitive position in strengthening. Conversely, a negative moat trend indicates that it is weakening. These moat trends have been an excellent indicator of stock performance.
In the video below, Fool contributor Daniel Sparks discusses the importance of these ratings and he suggests one way investors can identify positive and negative moat trends. To illustrate, Daniel takes a look at Apple (AAPL 4.08%), Whole Foods (WFM), and Nokia (NOK 0.98%).