Estimated tertiary periods as a function of inner binary period. Identified Robo-AO candidate triples are marked as red (Torres et al. 2010) and orange (Troup et al. 2016) arrows, given that our estimates are upper limits. For comparison, we plot the updated MSC triples (Tokovinin 2018) as gray plus signs while overplotting the triples from the volume-limited Raghavan et al. (2010) sample as black plus signs. For reference, the dashed line represents P3 = 103.5P1. The dynamical stability limit for triples (P3 = 4.7P1) is shown by the solid line. Known PMS (≲30 Myr) triples are shown in blue.