Spendthrift releases 2019 prices for its 25-strong roster in the US

Into Mischief will command a $150,000 fee at Spendthrift Farm next yearCredit: Racing Post Photos

Into Mischief's fee will rise by 50 per cent, from $100,000 to $150,000 (£115,000/€130,000) for the 2019 season – however, the son of Harlan's Holiday is already fully booked.

The Spendthrift resident was responsible for this year's Florida Derby winner Audible while his son Instagrand, a $1.2 million breeze-up purchase, took out the Grade 2 Best Pal Stakes at Del Mar in August, though will miss out on the rest of the season.

Joining the roster at B Wayne Hughes's Kentucky stud will be a trio of Grade 1 winners in Mor Spirit, Free Drop Billy and Bolt D'Oro, who remains in training until the end of the season.

Bolt D'Oro, who will be introduced at a $25,000 fee, took out last year's Del Mar Futurity as well as the FrontRunner Stakes at Santa Anita. The son of Medaglia D'Oro won the Grade 2 San Felipe Stakes in March before finishing second to Triple Crown hero Justify in the Santa Anita Derby.

Goldencents, an eight-year-old son of Into Mischief, is the leading first-season sire in North America by earnings, with his fee jumping from $12,500 up to $20,000. He has notched up 19 winner already this season – seven more than any other freshman sire in North America.

Malibu Moon – responsible for this year's repeat Bing Crosby Stakes scorer Ransom The Moon and Arkansas Derby winner Magnum Moon – remains at $75,000.

Spendthrift is introducing a new breeding incentive for 2019 called the Safe Bet Program, which is designed to substantially minimise risk for breeders who support any of Spendthrift's fourth-year stallions who have first-crop two-year-olds set to hit the track in 2019.

The programme was designed to assure breeders of a significant level of success from a stallion's first crop of two-year-old runners, or the breeder will pay a significantly discounted stud fee.

Spendthrift Farm fees for the 2019 breeding season

Sire, damsire, stands and nurses fee

Into Mischief Harlan's Holiday $150,000 – book full

Malibu Moon A.P. Indy $75,000

Bolt D'Oro* Medaglia D'Oro $25,000

Lord Nelson Pulpit $25,000

Goldencents Into Mischief $20,000

Jimmy Creed Distorted Humor $20,000

Cross Traffic Unbridled Song $10,000

Gormley Malibu Moon $10,000

Mor Spirit* Eskendereya $10,000

Temple City Dynaformer $10,000