A 2.5% share in Flightline, who sealed his place among racing’s legends with an eight-and-a-quarter-length romp in the million Breeders’ Cup Classic on Saturday, was sold at Keeneland for $4.6 million on Monday.

Brookdale Farm’s Freddy Seitz signed the ticket on behalf of an undisclosed client who was described by Seitz as a small-scale owner-breeder who wanted "to make a big splash" in the bloodstock world.

The fractional interest, offered by West Point Thoroughbreds, sold during a special auction prior to the start of the premier Book 1 session of Keeneland’s November Breeding Stock Sale.

In theory Flightline has a book value of $184 million, based on today's sale.

“(The buyer) just called and said, ‘I really want to make a big splash and get involved a little more in the business,’ ” said Seitz, who was on the phone with the buyer during the bidding.

“I did not expect (the price) to go that high. It was pretty exciting. When you’re dealing with top quality, you’ve got to pay. (The buyer) did not give me that kind of figure going in. I could tell once (the bidding) started maybe we were going to keep going. I was a little more nervous than he was. He and his family were watching. I think they were having a really good time.

“With a special horse like (Flightline) all you can do is get involved and then just hope for the best,” Seitz added. “There has never been a horse that has done what he has done for however many years, back to Secretariat.

"You just have to pay up and get involved, and this is kind of what he’s thinking. He has a broodmare band and I think he is going to have a nicer broodmare band now. He does have some nice mares – six or eight mares at any time. He will probably be shopping now from what I understood.”

Flightline is undefeated in two seasons of racing, with four of his six career wins coming in Grade 1 stakes: the aforementioned Breeders’ Cup Classic at Keeneland, TVG Pacific Classic, Hill ‘n’ Dale Metropolitan Handicap and Runhappy Malibu. He has amassed earnings of more than $4.5 million.

On Sunday, it was announced the four-year-old son of Tapit has been retired from racing and will enter stud next year at Lane’s End Farm in Versailles, Kentucky.

“It was very exciting; it’s a tribute to Flightline,” Bill Farish of Lane’s End said. “He’s just an incredible horse. There was a tremendous amount of interest.

"It was so hard to know where something like that would go. It’s the first time anything like this has ever been done with a horse of that magnitude. And there was only one (share) available. It’s an incredible opportunity and only because it’s Flightline.”

The November Breeding Stock Sale continues until November 16th.