What can cause a massive drop in price?

[jquik]

Potentially a pretty newbie question here but something I've always wondered and there is a relevant example today! In the 8.05 at Hexham today, Lifes A Mystery was 25/1 with Hills and in the space of 15 minutes, is now 9/2 at Hills (and a best price of 6/1 elsewhere!). Boyles have even cut it to 3/1! Although being really interested in racing, I will be the first to admit I don't really know that much about it... and I haven't the faintest how such a HUGE price cut can occur? Are there any particular factors or is it sometimes just a massive gamble?

[alexmac]

Re: What can cause a massive drop in price? Just the liability of the bookies I would imagine.