Magnitudes of the azimuthal velocity components v_ϕ of 4 M_⊙ HVSs in Newtonian gravity as a function of their radial coordinates, r, at the time of observation for a prolate dark matter halo with axis of symmetry in the plane of the disk. The light blue and purple dots show the HVSs for a halo with (q_y, q_z) = (1.1, 1) and (q_y, q_z) = (1.2, 1), respectively. The black line shows the upper limit of |v_ϕ| in QUMOND due to the triaxial bulge. The upper limit also holds for HVSs with masses lower than 4 M_⊙, provided they are beyond a certain galactocentric distance, e.g., r ≳ 30 kpc (50 kpc) for 3 M_⊙ (2.5 M_⊙) HVSs.