Seize The Grey is out of Smart Shopping (Smart Strike), a two-year-old winner who was placed in the Listed Suncoast Stakes. He is a half-brother to Shoppingforpharoah (American Pharoah), a two-year-old winner and Listed-placed.

Second dam Shop Again (Wild Again) won the Listed Ada Stakes. Besides Smart Shopping she has five winners, among them the sire Power Broker (Pulpit), winner of the Grade 1 Frontrunner Stakes and placed in the Grade 1 Haskell Invitational Stakes, and Fierce Boots (Tiznow), winner of the Listed Busanda Stakes and dam of Portos, a dual winner who was Grade 3-placed.

Third dam Shopping (Private Account) won three times and produced nine winners. Besides Shop Again they include Miss Shop (Deputy Minister), winner of the Grade 1 Personal Ensign Stakes and placed in the Grade 1 Ruffian Handicap, the sire Trappe Shot (Tapit), a Grade 2 winner placed in the Grade 1 Haskell Invitational Stakes, and Bought In Dixie (Wild Again), a Listed winner who was Grade 2-placed. Miss Shop is the dam of Tin Type Gal, a Grade 3 winner and Grade 2-placed.

This is also the family of the sire Invader (Snitzel), co-champion two-year-old colt in Australia in 2016-2017, who won the Gr.1 Sires' Produce Stakes and was placed in the Gr.1 Champagne Stakes.