A flurry of £100 bets on Bob Dylan has seen the singer-songwriter leapfrog over the likes of Philip Roth and Cormac McCarthy to become the second favourite to win the Nobel prize for literature this autumn.

Dylan is now at 10/1 to win the award, with only the cult Japanese novelist Haruki Murakami in a better position with odds of 7/1, according to Ladbrokes. "[Dylan has] been backed from 33/1 into 10/1 thanks to some decent £100-plus bets … One of the big bets comes from Norway, the others are UK-based," said the betting firm's spokesman Alex Donohue, who revealed that the average stake on Dylan to win the Nobel was around £40, "high for this market when most people tend to have a tenner on their selection".

As well as his musical output, Dylan is the author of a legendarily incoherent prose and poetry collection Tarantula (1971) and was the subject of a reverent work of literary criticism by former Oxford Professor of Poetry Christopher Ricks. His literary stock rose with his acclaimed 2004 memoir Chronicles and recently revealed that he is working on a sequel. Quite apart from Swedish Academy member Horace Engdahl's professed hostility to "parochial" American writing, this seems unlikely to bring him to the head of the queue for literature's most prestigious award.

Although Dylan's name emerges annually as a possible contender, Ladbrokes believes it is highly unlikely the singer will win the world's most prestigious prize for literature. "We're happy to 'fill the satchel' in bookmaking terms as we expect the Dylan backers to part with their cash again this year," said Donohue.

MA Orthofer, founder of international literature website the Complete Review, was also sceptical about Dylan's chances. "If you know anyone who has actually generously donated money to Ladbrokes by 'betting' on him please try to get them professional help, either from a psychiatrist or an accountant," he blogged.

Ladbrokes has also seen a "steady stream of money" for British novelist Ian McEwan, whose odds have tumbled from 100/1 to 50/1, while according to Donohue, Czech writer Milan Kundera is "another well-fancied outsider" at 66/1. Murakami, however, "remains on course to stay favourite throughout the betting heat, even if the money continues to pour in for Dylan".

The Nobel prize for literature is awarded to "the most outstanding work in an ideal direction", and Orthofer noted that playwright Tom Stoppard had also moved from 66/1 to 16/1 at Ladbrokes. "Remember that final deliberations for the winner have not yet begun – and won't for two more weeks; new names and odds-changes might indicate some information about who is on the shortlist, but given that Harold Pinter won only a few years ago I have my doubts another British playwright is already back in the running, and as far as Dylan goes … oh, get serious people: he is not in the running, never has been, never will be," he wrote.