[5] As a yearling the colt was consigned to the Keeneland Sales in September 2013 and was bought for $200,000 by Jim McIngvale,[6] who made his fortune in the furniture business.

Runhappy made his first appearance in a maiden race at over six and a half furlongs on the synthetic track at Turfway Park in Kentucky on December 28.

[7] On his three-year-old debut, Runhappy was moved up in class for the Grade III Lecomte Stakes at Fair Grounds Race Course in New Orleans on January 17.

On a fast track at Ellis Park Race Course later that month, he won a six and a half allowance, leading for most of the way to beat Springboard by two and three quarter lengths.

[10] Edgar Prado took over the ride when Runhappy was moved up sharply in class for the Grade I King's Bishop Stakes over seven furlongs at Saratoga Race Course on August 29.

"[11] On October 2, the opening day of the Keeneland Fall meeting, Runhappy started 7/5 favorite for the Grade III Phoenix Stakes over six furlongs on a sloppy track.

Holy Boss was again in opposition, but the main danger appeared to come from Work All Week, the reigning American Champion Sprint Horse.

Ridden again by Prado, Runhappy led for most of the way and kept on in the straight to win by one and three quarter lengths from Hutcheson Stakes winner Brabados, with Work All Week taking third ahead of Holy Boss.

[14] At Keeneland on October 31, Runhappy, ridden again by Prado, started 8/5 favorite in a fourteen-runner field for the Breeders' Cup Sprint.

Runhappy, however, had always been going well behind the leaders and ran on strongly in the closing stages to take the lead 75 yards from the finish and win by three quarters of a length from Private Zone in a track-record time of 1:08.58.

[16] On November 1, the day after the Breeders' Cup, Wohlers, acting as racing manager for McIngvale, dismissed Borell from her position as the colt's trainer.

Borell claimed, however, that she had been dismissed because she refused Wohlers' request to send the colt to the track for exercise after finding heat and mild swelling in one of his legs.

[17] The ensuing debate between the parties initially played out largely on social media for several days until Borell filed suit against McIngvale on November 10, 2015, alleging breach of contract and defamation.

[20] McIngvale had a long history of summarily firing horse trainers, over 30 As of 2015[update], including Hall of Famers Bob Baffert and Bobby Frankel.

[21] In January 2016, Runhappy was named American Champion Sprint Horse for 2015 at the Eclipse Awards after taking 255 of the 261 votes.

[24] He was initially targeting the Grade II Churchill Downs Stakes,[25] but slight bruising on his right hind heel delayed his return to the races by a few weeks.