Queensland filly Isotope has been the key firmer overall with Sportsbet.com.au for the Arrowfield Sprint (1200m) this Saturday at Randwick.
The Tony Gollan trained three year old resumed with a strong win in the Darby Munro and should be further suited on the firmer track. $4.40 was first put up on Tuesday and she now sits at $3.60.
Favourite for the race is the class runner of the field, September Run. $2.25 was her price on Tuesday, which was silly short. Got to $3.40 but is now at $3.20.
They dominate betting, with Wild Ruler next best at $7.