With a simple number formatting trick, you can create and Excel chart as shown below:

You can see the negatives values in chart data labels are highlighted in Red and all the values have either an upward or downward arrow with it. To create this, right-click on the chart data labels and select Format Data Labels (shortcut – Control + 1). In the Format Data Labels task-pane, select Number, and make the formatting as shown below:

Here I have specified the number formatting when the value is positive and when it is negative. Arrow symbol in double quotes ensures that it is added before the value in the data label. (Read more about Excel Number Formatting)

Neat Trick.. Isn’t it!! Try it yourself.. Download the file

Spice Up Excel Chart Data Labels – Show Positive/Negative Trend Arrows.