James Maxwell
Founder & Editor · Last reviewed 2026-04-12
Bookmakers' Worst Day in Years
When I Am Maximus crossed the line at Aintree on Saturday afternoon, the cheers from the stands were matched in volume only by the silence in bookmakers' trading rooms across the country. The 9/2 favourite had won, and the industry was facing one of its most expensive Grand National payouts in living memory.
One major bookmaker described the day as delivering "a payout of north of £10 million" — an historic figure for a single race. Across the board, layers who had taken substantial ante-post and day-of-race money on I Am Maximus were left to count the cost of a punter-friendly result.
William Hill spokesman Lee Phelps did not mince words: "We're reeling from what looks like an historically high payout in the Grand National. This is a payout we're going to remember for a long time to come."
The scale of the losses was driven by three factors: I Am Maximus's popularity as a previous winner, his dramatic on-the-day market support that saw him smashed in from 8/1 to 9/2, and the placed return for Johnnywho in fourth, which caught bookmakers who had already stretched to seven each-way places.
For punters, it was a rare day when the public beat the market decisively. For bookmakers, it was a reminder that favourites can — and do — win the Grand National.
The £100,000 Bet That Paid £800,000
Among the many stories to emerge from Aintree on Saturday, one stands out above all others on the betting side. An unnamed racegoer placed a £100,000 single bet on I Am Maximus to win at odds of 8/1 with an on-course bookmaker.
When the horse crossed the line first, the bookmaker faced a liability of £800,000 on that bet alone.
The story drew immediate attention from the racing world and beyond. A £100,000 bet is extraordinary in any context. At 8/1, the potential return of £900,000 (stake plus winnings) represents a life-changing sum. The punter had clearly done their homework — they placed the bet before I Am Maximus was sent off at his much shorter starting price of 9/2.
Timing was everything. By taking the 8/1 early price rather than the SP, the punter locked in a return more than double what they would have received at the morning-of price. The market moved sharply throughout the day as money poured in for the favourite.
The on-course bookmaker who accepted the bet reportedly confirmed the payout was made in full. When pressed, a spokesman acknowledged it as "one of the biggest single bets we have ever paid out on the Grand National."
It is not known who placed the bet. On-course bookmakers are not subject to the same know-your-customer requirements as online operators and can accept large cash wagers without the scrutiny that would apply in a licensed online environment.
What is known is that somewhere, someone is having a very good Sunday morning.
How the Market Moved: 8/1 to 9/2
One of the clearest signs that the public knew something on Saturday was the dramatic movement in I Am Maximus's price throughout the day.
He opened the morning at around 8/1 — reflecting some caution from bookmakers. He was a previous winner, yes, but he had finished second in 2025 behind Nick Rockett, and carrying top weight of 11st 12lb was widely seen as a potential disadvantage. Early ante-post markets had him as favourite, but race-day traders had their doubts.
The money told a different story.
From the first show of prices on Saturday morning, I Am Maximus was backed consistently and heavily. William Hill described him as "absolutely smashed" from 8/1 into 9/2. BetVictor spokesman Sam Boswell confirmed he "was always in our top three for bets taken all day long" and had been their ante-post favourite "for a long period of time."
By the time the field left the start, I Am Maximus was the clear market leader at 9/2 — a move of over four points from his opening price. In betting terms, that is a significant shift in a single morning.
| Time | Approximate SP |
|---|---|
| Ante-post (week before) | 5/1–6/1 |
| Morning of race | 8/1 |
| Mid-morning | 6/1 |
| Pre-race show | 9/2 |
| Starting Price | 9/2 |
The lesson for the bookmakers is one they know but rarely enjoy experiencing: when a previous Grand National winner returns healthy and well-fancied, the public gets behind them in enormous volume. Hedging that liability in a 34-runner race is difficult. On Saturday, it proved impossible.
Bookmakers React: "This Is One We Will Remember"
The industry has been vocal in the wake of Saturday's result — more so than is typical after a Grand National. That itself says something about the scale of the pain being felt.
William Hill were among the hardest hit. Spokesman Lee Phelps said: "Him winning was one of our worst-case scenarios. 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."
BetVictor's Sam Boswell added: "I Am Maximus could be popular come the day as a previous winner and he was our ante-post favourite for a long period of time. He was always in our top three for bets taken all day long." BetVictor declined to confirm their exact liability but confirmed it was "a significant result" for the firm.
Smaller operators faced a proportionally similar challenge. The Grand National is one of the few races where non-regular punters place bets — often on a previous winner, a horse whose name they like, or an animal associated with a big-name owner like JP McManus. All three of those factors applied to I Am Maximus in abundance.
The situation was compounded by the each-way market. Major bookmakers had extended to seven each-way places to attract customers. When Johnnywho, a relatively fancied runner, finished fourth, it triggered additional payouts that would not have applied under standard terms.
It was, by any measure, a day to forget for the layers — and a day punters will be talking about for years.
Grand National 2026 Betting — Frequently Asked Questions
How much did bookmakers lose on the 2026 Grand National?
Bookmakers collectively paid out over £10 million on the 2026 Grand National, according to industry sources. William Hill described it as "an historically high payout" for a single race.
What was the biggest bet on the 2026 Grand National?
The largest reported single bet was £100,000 placed on I Am Maximus at 8/1 with an on-course bookmaker. That bet paid out £800,000.
Why did I Am Maximus shorten so much in the market?
I Am Maximus opened at approximately 8/1 on the morning of the race but was heavily backed throughout the day, tightening to 9/2 SP. He attracted enormous public support as a previous winner and the ante-post favourite. His connections' confidence and the market moves of professional punters contributed to the dramatic drift.
Which bookmaker lost the most?
William Hill were among the most vocal about their losses. No single bookmaker has confirmed the exact figure lost, but multiple firms described the result as one of their most expensive Grand National outcomes.
Did the each-way terms make things worse for bookmakers?
Yes. Most major bookmakers extended to seven each-way places for the 2026 Grand National. Johnnywho finishing fourth increased payouts significantly for bookmakers who had taken large each-way liabilities.
Do bookmakers ever win on the Grand National?
Yes — most years, bookmakers profit from the Grand National because the public backs favourites, longshots often run well, and the race's unpredictability typically works in the layers' favour. Saturday was an exception: the hot favourite won, the places were filled by backed runners, and the volume of money on the winner was unusually high.
What does this mean for Grand National odds in 2027?
Bookmakers may be more cautious with I Am Maximus in 2027 if he returns, pricing him up more tightly early and limiting ante-post stakes. However, the economics of the Grand National — where public interest drives huge turnover — means they are unlikely to significantly restrict access to the market.
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