Quarter Moon is a bay mare with no white markings bred in Ireland by Premier Bloodstock, a breeding company owned by John Magnier of the Coolmore Stud and Richard Henry.
Jude's dam Alruccaba was an influential broodmare whose other descendants have included Alborada, Allegretto (Prix Royal Oak), Aussie Rules (Poule d'Essai des Poulains) and Albanova (Preis von Europa).
[2][6] Rather than making her first appearance in a maiden race Quarter Moon made her track debut in the Group 3 Debutante Stakes over seven furlongs on soft ground at the Curragh on 19 August.
Starting at odds of 5/1 she was restrained in the early stages before producing a strong late run and failing by only a head to overhaul the Dermot Weld-trained favourite Saranac Lake.
Quarter Moon was then moved up in distance for the Epsom Oaks over one and a half miles on unusually soft ground on 7 June and started 15/2 fourth favourite behind Kazzia, Islington and Mellow Park.
[12] On 14 July at the Curragh Quarter Moon started the 4/5 favourite for the Irish Oaks but after taking the lead in the straight she was overtaken inside the final furlong and beaten a length by the 33/1 outsider Margarula.
Onher her final appearance she was sent to France to contest the Prix de l'Opéra over 2000 metres at Longchamp Racecourse on 6 October and finished unplaced in a race won by Bright Sky.