The opposite of an odds-firm, a blow-out is when a particular horse goes cold in betting markets in the lead-up to a race, and its odds get longer and longer.
Also called an odds-drift, the unfancied horse is a drifter, and late money is suggesting that he/she won't be in the finish.
"I'm absolutely spewing! I backed this roughie at $20 and now its blown out to $50. I should have stuck with the favourite."
