William Hill stopped taking bets on the ITV soap whodunnit yesterday at 9.46am after a "monster gamble" on rogue Tony Stewart from punters cut his odds from 100/1 to 2/1.
McIntyre - played by Michelle Keegan - will be seen falling from a balcony at the builders' yard after a dramatic confrontation with her killer on May 27. Her brutal end launches a hunt which will grip Weatherfield.
William Hill spokesman Rupert Adams said: "There was a real rush to back Tony - including a number of new account openings. We fully expect Tony to be unveiled as having done the dastardly deed!"
The odds on the killer are 4/6 for Rob Donovan, 2/1 Tony Stewart, 5/1 Peter Barlow, 10/1 Carla Barlow and 16/1 for Tracey Barlow.
Michelle Connor and Simon Barlow were at 25/1 to be named as the culprit while Owen Armstrong, Steve McDonald and David Platt who were all at 33/1.
Odds of 50/1 have been available for Tyrone Dobbs, Dennis Tanner, Dev Alahan, Gary Windass, Jason Grimshaw, Kylie Platt, Lloyd Mullaney, Nick Tilsley, Tim Metcalfe and Todd Grimshaw to be named as the killer.
In the build-up to the death, viewers will have a chance to watch four alternative showdowns between her and potential killers - Peter Barlow, Carla Barlow, Rob Donovan and Tracy Barlow - which are being made available on the official Coronation Street website, itv.com/coronationstreet.
Producers of the show say there will be a "shocking twist" next Wednesday, the night after her death plunge, just as the police begin their efforts to track down who is responsible.
In the coming months, the audience will see the killer desperately trying to cover their trail and evade justice.
Keegan has admitted she was surprised when she discovered that Tina was being written out for good and there would be no coming back.