The online bookmaker suspended betting on their next Premier League manager to go market on Monday afternoon after seeing McDermott backed in from 20/1 to as a short as 1/4.
The development was followed shortly after by confirmation that McDermott had been sacked, with the Royals four points adrift of safety and favourites for relegation following a fourth successive Premier League defeat.
Di Canio is available having left Swindon last month and is the early favourite having attracted a large majority of the backing, followed by Nigel Adkins and Roberto Di Matteo.
Sky Bet's Chris Spicer said: "It became clear that somebody knew something we didn't at around 4pm as bets suddenly flooded in for McDermott to be the next boss to go, prompting us to cut his price and then eventually suspend betting.
"While the money to follow is likely to paint a clearer picture, Di Canio has attracted the early money following his impressive work at Swindon."


























