It is, quite literally, the most bet-upon sporting event in the UK each year.
And it’s usually one that the bookmakers do rather well at too, as casual punters pile in with bets placed on horses that share the same name as their favourite aunt/work colleague/cat etc.
But this year at Aintree, the biggest Grand National gamble paid off, as punters backed I Am Maximus in their droves… and watched on as Willie Mullins’ horse landed a second win in the showpiece steeplechase.
It’s a result that cost the bookies millions… including a single £900,000 pay out from Fitzwilliam that the firm’s owner has since confirmed was a genuine bet.
Maximus Painus
William Hill spokesperson Lee Phelps has confirmed that the heavily backed I Am Maximus, who also won the Grand National in 2024, has cost his firm a ‘historically high’ loss.
“He was absolutely smashed before the off from 8/1 into 9/2 and we’re reeling from what looks like an historically high payout in the Grand National,” Phelps confirmed.
“We’re facing up to a payout of north of £10 million in the race.”
“We’re licking our wounds and this is a payout we’re going to remember for a long time to come.”
Meanwhile, Betfred’s Fred Done described the result as a ‘gladiatorial bloodbath’, while Paddy Power’s Paul Binfield has confirmed that his firm ‘took a battering’.
“It was a bruising result – punters have had it right off, getting involved in what was a mammoth public gamble,” Binfield said.
I Am Maximus was well backed at prices ranging from 8/1 to 9/2, and to make matters worse for the bookies, two more well-fancied contenders – Iroko and Johnnywho – helped to fill out the each way places.
Expensive PR
J.P. McManus has played his part in some of the most iconic Grand National moments.
The Irish owner provided Tony McCoy with his long-awaited win in the Aintree spectacle aboard Don’t Push It in 2010, before Rachael Blackmore became the first female jockey to win the Grand National on McManus’ Minella Times in 2021.
Next year, McManus could also be celebrating another famous moment if I Am Maximus can become the first three-time winner of the Grand National since the legendary Red Rum all those years.
The Irish billionaire is rarely shy of backing his horses before the off as well, and rumours persist that it was he who placed a whopping £100,000 on I Am Maximus to win the Grand National on Saturday.
The unfortunate bookmaker to cop the gamble was Fitzwilliam, who had the popular frontman Johnny Dineen working their pitch at Aintree.
Someone has just placed ONE HUNDRED THOUSAND pounds on I Am Maximus to win the Grand National 😳#ITVRacing pic.twitter.com/uTRn1OnFUF
— ITV Racing (@itvracing) April 11, 2026
Dineen, and the rest of the Fitzwilliam team, have refused to name who placed the monster wager, which saw the firm pay out £900,000 to the mystery punter alone – before promptly paying out all the others at trackside that had backed McManus’ stayer.
And Dineen’s colleague Michael Gannon later revealed that the big payout had even threatened the company’s future – claiming they would ‘work around it so we don’t go into liquidation.’
There were even claims that the bet was fabricated for PR purposes, but Fitzwilliam boss Paul Byrne has confirmed that it was real – and the most his outfit has ever had to pay out to a single winner.
“It was a real bet,” Byrne confirmed to Racing TV.
“Someone wanted to back the horse; 8/1 was freely available, there was 9/1 in places and I thought it was an opportunity to get the bet away.
“There was about three hours before the race. At the time the exchanges were looking full of opportunities to get away at a bigger price.”
Although his traders would have been able to limit their liability somewhat by backing I Am Maximus in the betting ring and online, the horse’s price fell so sharply before the off that Fitzwilliam, and others, faced an almighty battle to balance their books.
“It was panic stations come the end just to get rid of the money and I think that was most likely the reason for the SP. I was surprised how weak the market became for our marquee race.”
Perhaps we’ll never know if it was McManus who placed the £100,000 bet. But with a net worth of an estimated £1.5 billion – and £500,000 paid to winning connections at the Grand National – maybe it doesn’t make that much of a difference anyway.