Who Is Magnitude? The $9.6M Earner Retired Before the Classic

Magnitude racehorse: who he is and why he left the Classic

Magnitude is a 4-year-old colt by Not This Time, trained by Steve Asmussen for Winchell Thoroughbreds, and one of the best dirt horses of his generation. The Magnitude racehorse story took its last turn on Thursday, Oct. 29, 2026, when he was withdrawn from the Breeders' Cup Classic on veterinary advice and retired.

He had drawn post 6 at 6-1 on the morning line, with Flavien Prat named to ride. Asmussen told Daily Racing Form that a PET scan "revealed some disruption in the suspensory fibers of his left foreleg."

After talking with Ron Winchell and David Fiske of Winchell Thoroughbreds, the team chose to "err on the side of caution and not take any risk with a tremendous horse." Asmussen said he was "nothing short of heartbroken."

No also-eligible had been drawn, so the field fell from eight to seven. US Racing called that the smallest field in the Classic's 43-year history, saying the race had never been run with fewer than eight. Horse Racing Nation had reported the same eight-horse floor before the scratch.

For the race itself, see our Breeders' Cup Classic field guide. This page is about the horse.

Magnitude's career at a glance

His family has class on the dam's side too. His second dam, Octave, was a Grade 1 winner at 1 1/8 and 1 1/4 miles.

The turning points of his career

The Risen Star and the bone chip (2025)

Magnitude had just two wins from six starts when he went to the Risen Star (G2) at Fair Grounds on Feb. 15, 2025. He won by 9 3/4 lengths at 43-1, and earned a 108 Beyer Speed Figure, the best of his generation at that point.

Three days later he was off the Kentucky Derby trail. A funny step two days after the race pointed to pain in the joint, and X-rays found a chip in his left front ankle. He shipped to Kentucky for surgery with Dr. Larry Bramlage at Rood and Riddle Equine Hospital on Feb. 19.

He came back that year and showed the talent had survived:

• Iowa Derby (Listed): won by 9 1/4 lengths
• Travers (G1): third at Saratoga, 20 3/4 lengths behind Sovereignty
• Pennsylvania Derby (G1): second
• Clark (G2): beat older horses by a half-length at Churchill Downs

The Saudi Cup that never happened (2026)

His 4-year-old season was built around the $20 million Saudi Cup on Feb. 14. A minor illness kept him from shipping, so Asmussen changed course.

He ran instead in the Razorback Handicap (G3) at Oaklawn Park on Feb. 28, winning by 3 3/4 lengths as the 4-5 favorite. That made the Dubai World Cup his next target.

The Dubai World Cup (March 28, 2026)

This was the race that made him famous worldwide. Under Jose Ortiz, Magnitude broke sharply at Meydan, led all the way and beat Forever Young, the odds-on favorite and reigning Breeders' Cup Classic winner, by a length.

He ran the 2,000 meters in 2:04.38. It was Asmussen's second Dubai World Cup, after Curlin in 2008.

The Stephen Foster and the Coolmore deal (summer 2026)

On June 27 he won the $2 million Stephen Foster (G1) at Churchill Downs by 1 1/4 lengths over Baeza, with Sovereignty, the 2025 Horse of the Year, third. It earned a 114 Beyer.

On July 28, Coolmore's partners announced a deal with Winchell Thoroughbreds for his breeding rights. Terms weren't disclosed. Winchell kept racing him, with Ashford Stud waiting after his career.

The Whitney (Aug. 8, 2026)

He went to Saratoga unbeaten on the year and left with the worst day of his 4-year-old season. The 9-5 favorite stumbled at the start, faced a hot pace and finished sixth of seven, about 15 lengths behind Sovereignty.

The next morning Asmussen called it "a disappointing run" and said the colt "never was comfortable," though he looked fine afterward. He then trained straight toward the Classic, and it would have been his final race. Five works at Keeneland followed, including a bullet.

What the suspensory ligament does

The suspensory ligament runs down the back of the cannon bone, the long bone below the knee. Near the fetlock (the ankle) it splits into two branches that attach to the small sesamoid bones behind the joint. You can trace it on our anatomy page.

A 2024 review by Royal Veterinary College and University College London researchers in the Equine Veterinary Journal describes three main jobs:

• Sling: it holds up the fetlock and stops it from overextending when the leg takes weight.
• Spring: it stores energy as the leg loads and gives it back, which makes each stride cheaper.
• Support at rest: it helps horses stand for long periods with little muscle effort.

Those jobs are why injuries matter so much in a racehorse. The review puts suspensory injuries in Thoroughbred racehorses at about 2.7 per 1,000 starts, and says up to 68% of Thoroughbreds don't race again after one.

Those figures describe suspensory injuries in general, not this horse. His team has not released a grade, a prognosis or a detailed veterinary report, and nothing reported links this finding to the 2025 ankle chip.

If you own a horse

Leg swelling, heat or lameness, even when it comes and goes, is a reason to call your vet rather than wait. The health basics section covers what to watch for in daily checks. For how raceday exams work, read what a vet scratch is.

Why a future stallion's team would not risk him

Magnitude's retirement was already planned. Coolmore America confirmed that Ashford Stud for 2027 had been the plan after the Breeders' Cup, so this cost him one race, not his stud career.

That changes the arithmetic in plain ways:

• The downside is permanent. The suspensory takes huge load at racing speed, and a serious injury can end far more than a season.
• The upside is one afternoon. He had already proved himself with two Grade 1 wins at 4.
• Stallion work is physical. Registered Thoroughbred foals must come from live cover, so he has to do the job in person. See how stud fees work.
• There is no do-over. Once a scan raises a concern, running anyway can't be undone. No purse changes that.

The welfare answer and the business answer pointed the same way. That doesn't always happen in racing, which is why decisions like this get noticed.

What to watch next at Ashford Stud

This page will stay useful long after the Classic, because his next career is just starting. Here's the usual Northern Hemisphere calendar for a new stallion:

For scale, his sire Not This Time stood for $250,000 in 2026. That's a benchmark for the family, not a forecast of Magnitude's fee.

Three things will tell you how breeders see him:

1. The fee. It's Ashford's first public statement of his value.
2. His first book. Watch how many mares he covers and how good they are.
3. Sale prices in 2029. Yearling buyers give the first market verdict on his foals.