In this example, the accents are above the notes:
What if you were accenting middle C? Would the accent go above the stem?
Horizontal accent marks, that look like '>', go close to the note head in single voice music (c.f. page 9-10 of this style guide). In multi-voiced music, the accents for the upper voice(s) are above the music, and thus are "on top of the stems", and the accents for the lower voice(s) are below.
The convention to keep '^' style accents above the notes, whether stem up or stem down, as indicated here, makes sense to me, but I don't have what I consider to be an authoritative reference on it (It's just that I've never seen it, and when I imagine it, it would look weird to me.)