There are two methods (as far as I know) to emphasise the last point on a sparkline. Here is how. Please note that the diagrams/gif is not a final representation of what a sparkline should look like, it only shows the method for emphasising the final data point.
Although this method is simple, it has the problem that the text label will always be in the view. This means that you might see a bit of overlap between the text and the line in your final dashboard. Another drawback is that the size of the dot cannot be changed. From my experience, this is not a problem due to the typical size of sparklines.
Whatever the background to the sparkline is, make sure you match the font’s colour to it. Also, be careful about the font sizing. It is fiddly when changing it to font size 1.
1. Create a LOD calculation like the one below. Bare in mind that I have a Date field in the columns and Sum(Sales) in the rows.
2. Dual axis this calculation and synchronise the axis
3. Customise as you’d like