Left: colour-magnitude diagram of NGC 3532 highlighting the identified rotators (black outline). Rotation periods have been measured for the majority (detection fraction > 50%) in the G2 to K8 spectral type range. The colour scheme is the same as in Fig. 3, with radial velocity members of NGC 3532 in orange and additional proper motion members in blue. Likely cluster binaries are marked with squares. Right and bottom: histograms showing the fraction of periodic rotators identified among the members. The decline for (V − K_s)₀ > 3.2 and V₀ > 16.5 arises from the decreasing sensitivity for fainter stars.