If you have the Track Pane open (Track View)
You will see some menu buttons with drop-down arrows, just above the track names and clips.
These include: View, Options, Tracks, etc...
Click on the arrow on the right side of the Options menu button, to expand its drop-down choices.
One of these choices is: On Stop, Rewind to Now Marker
If this option is checked, then when play stops, Sonar will do just that, and rewind you to wherever the Now Marker is set. This is what I use for normal tracking/recording, and simple playback, so that I can cruise through sections of a track and then go back to where I had started the playback to decide then what next to do.
When that option is NOT checked, then when playback is stopped, Sonar will simply stop at that point. I typically DO have the option unchecked during EDITING of a track's data, and so as I work through some troubled part of a track, I very much want to keep the positioning within the track I am editing, right where I am working - so I do not during edits want Sonar rewinding anywhere.
That's the beauty of using this option, that there IS this level of control, checked for tracking/playback, and unchecked for editing. (of course, there are frequently times during editing that I also have the option checked to rewind, and it all comes down to whatever works best for what you are needing at any given moment. It's nice to have this choice).
Others may chime in with other rationale for setting this option one way or the other, it comes down to whatever works for what you are trying to do, and/or are more comfortable with doing.
I hope that was what you were looking for, (and that it helped)
Bob Bone