Mass ratio-period relation for planets orbiting low-mass stars. The y-axis shows the mass ratio m/M_* (for transiting planets) or m sin i/M_* (for non-transiting planets). The dashed horizontal lines indicate the mass ratios of Saturn and Jupiter compared to the Sun. The open symbols designate planets orbiting hosts with 0.3 M_⊙ < M_* ≤ 0.55 M_⊙, the filled symbols are for host masses M_* ≤ 0.3 M_⊙. Objects with small mass ratios, that is, terrestrial planets and super-Earths, are included for illustration, but not discussed further in the present paper. The data were compiled from the NASA Exoplanet Archive.