I wondered the same, I can only guess that the money it was attracting wasn't worth the effort of maintaining a market. The betting is still telling us nothing, at the moment Nolan shortening so quickly is more likely to be a damage limitation exercise from the bookies than anything else. His current price of 13/8 equates to a 38.1% chance that he will be the next manager and a 61.9% chance that he won't. Until someone goes shorter than 1/5 the odds offered should be only for interest.