Nicky Henderson has hailed the foresight of stable lad Conor Murphy after he won around £1million.
Henderson has sent out six winners at the Festival meeting this week, with Murphy having backed five of those in a bet struck last November.
Sprinter Sacre kicked off his winning spree with victory in Tuesday's Arkle, Simonsig in the Neptune Investment Novices' Hurdle and Bob's Worth in the RSA Chase obliged on Wednesday along with Finian's Rainbow, who Murphy looks after, in the Queen Mother Champion Chase.
Riverside Theatre's win in the Ryanair Chase on Thursday sealed the win for Murphy and Henderson reports his entire Seven Barrows team to be delighted at his good fortune.
"Everybody here is absolutely thrilled for him. It was just an amazing piece of foresight last November," he said.
"Just the chances of all of five getting to Cheltenham and all of them running in the right races, that would be long odds, particularly as with Simonsig we didn't even know what race he would be running in until the other week.
"The chances of them getting there since last November must have been at least 100-1 and the chances of them all winning, that must have been a 1,000,000-1!"
Despite his bumper payout, Henderson reports him to be at work in Lambourn this morning.
"He's in work this morning - he is one of the linchpins here. He's the most lovely man though, a fantastic guy and very quiet," the trainer continued.
"He rides out Finian's Rainbow every day of the week and he would probably know more than anyone else in the world about that horse.
"Finian's is very special to him."
The only Henderson-trained winner Murphy did not have in his accumulator was Une Artiste, who triumphed in Wednesday's Fred Winter at 40-1.
However, Henderson revealed that Murphy could not possibly have included that filly as she was not even part of his team at the time he placed the bet.
"He's backed five out of our six winners and he couldn't even have backed the other one last November as she wasn't in the yard then, she was still in France!" he explained.
"I had no idea it (the accumulator) was happening."
Jockey Andrew Tinkler, who is attached to Henderson's yard, joked that he would have headed off on holiday rather than attending morning stables.
He tweeted: "Can't believe that the million pound man was riding out this morning!!!! I'd be at Heathrow!!"
The wager was reported to be have been placed with Bet365 but they will not discuss the details.
"We've had a pretty horrendous meeting with plenty of favourites winning and there have been many, many winning accounts," said spokesman Pat Cooney.
"The one thing we never do is discuss individual accounts."
Bookmaker Paddy Power said the odds of the horses at the end of November, believed to be the month when the bet was placed, were Sprinter Sacre (10-1), Simonsig (14-1), Bobs Worth (10-1), Finian's Rainbow (8-1) and Riverside Theatre (9-1).
A spokesman for Paddy Power said: "That comes in at odds of 163,350-1. I'm glad we dodged that one."Murphy, who pointed to the triumph of Finian's Rainbow as a particular highlight of the five-timer, believes his winning streak was purely down to good fortune, but revealed the bet was actually placed a little later than previously thought.
"I still cannot believe it, even this morning it is still sinking in. I haven't even thought about the money yet. It was just pure luck," he told www.newburytoday.co.uk.
"I put the bet on just before Christmas in December, I just picked the five best horses and hoped for a lot of luck, I didn't think much about it.
"I wasn't really thinking about the bet when they all started coming in; you try so hard to get even one winner here, the day just draws you in."