The 6/9 chord combines a major triad with both a major sixth and major ninth — creating a lush, spacious voicing that is the ultimate jazz ending chord. It avoids the seventh entirely, sidestepping the major-vs-dominant question for a universally warm tonic sound.
The jazz ending chord: Nearly every jazz standard can end on a 6/9 chord. By including the 6th and 9th without a 7th, you get warmth and colour without committing to maj7 or dom7. Drop the 5th for a clean four-note voicing: root–third–sixth–ninth.