Cheltenham Festival Day 1 Market Movers: Supreme gamble into 8/1 from 20/1

• Betfair ambassador's runner popular this morning

• 14/1 into 13/2 market mover in the Ultima

• Last year's Mares' winner drifts in the market

Blackmore to start with a winner

Today's most backed horse on the Betfair Sportsbook is Inthepocket in the 13:30 Supreme Novices' Hurdle. Having opened up as big as 21.020/1, Henry De Bromhead's horse is now just 9.08/1 to prevail.

Inthepocket made it 2-2 under rules, winning a Grade 2 at Naas, before finishing second in the Grade 1 Tattersalls Ireland Novice Hurdle at Leopardstown.

Based on that performance, the six-year-old has 10 lengths to find on the winner, Il Etait Temps, who is the current 5.59/2 second favourite in the Cheltenham Festival opener.

However, Betfair punters believe Inthepocket was overpriced and there's been plenty of support for De Bromhead's horse this morning.

The Betfair Sportsbook is offering four places on the Supreme.

Marie's Rock weak in the market

Last year's Mares' Hurdle winner, Marie's Rock, hasn't proven to be a popular section amongst the Betfair faithful, drifting to 3.55/2.

Instead, there's been plenty of support in favour of Honeysuckle, who will run her last ever race this afternoon.

Despite four wins on the bounce, Nicky Henderson's horse isn't fancied to defend her crown, with many believing that this year's renewal is a much stronger race.

Popular punt in the Ultima

A positive market mover is Monbeg Genius in the 14:50 Ultima Chase. Having opened up at 15.014/1, he's now the 7.513/2 favourite to be first past the post.

The Betfair Sportsbook are offering seven places on the Ultima, which you can bet on here.

Monbeg Genius is a good jumper and has proven to be a stayer, having won his last three races at Newcastle and Chepstown over 2m7f and 3m.

Jonjo O'Neill's horse is up 8lb after his latest victory, but Betfair punters believe he looks capable of taking the step up and proving he can win on the biggest stage.