Newcastle began the 2026 season at $51 to win the premiership, according to newly released TAB data, before drifting to $101 after a round-eight defeat by Penrith.
Even after finishing in the top eight, Justin Holbrook's Knights were priced at $67 for the title.
One punter wagered $70,000 at $1.29 on Penrith to beat Newcastle in the preliminary final.
A Sydney Roosters-Newcastle grand final had been rated a $101 chance in pre-season betting.
Now the Knights are $2.85 outsiders to beat the Roosters and become the first top-grade team in more than 90 years to go from last to first in 12 months.
That turnaround followed a wooden-spoon season and gloomy forecasts from former Knights Andrew and Matthew Johns, despite their close ties to the club.
Andrew Johns questioned how new halves Dylan Brown and Sandon Smith would manage the team's spine, kicking and game control.
He wrote: "Game management is a massive test for Newcastle's new playmakers."
He also warned that Newcastle lacked depth in the forwards, with Jacob Saifiti and Trey Mooney named as starting props.
Mooney, Saifiti and Brown are all out for the season, but the Knights have overcome those setbacks.
Before round one, Matthew Johns said on the Backstage podcast that he did not expect Newcastle to make the finals, citing concerns about the forwards and the loss of Leo Thompson.
He said: "I haven't got them (playing finals football)."
The Johns brothers and the Hunter are now believers.