Now it is obvious that something is going on here with ROYAL ISLAND.
He is not even fav. yet has almost twice the volume of the fav. Look at his form figures - uninspiring to say the least

The jockey knows the horse and has won on him at this track over a year ago.
His prices for his last eight races 33, 80, 33, 40, 33,14, 20,16. And he has finished in the last 2 or 3 in all those races of big fields.
Now look what happened 9 races ago - he WINS at 2/1.
So, someone knows something and they appear to be betting accordingly -do you keep this in when when you trade.
The racing style of this horse is to come late and if you trade in running you need to have considered the history of this horse to know how you are going to trade him.