This is a very good theory!

But Tom didn't know he'd get the award for framing Hagrid.

When would Tom have had posession of the trophy to conduct the spell that turns it into a Horcrux, it seems that the awards stay at the school.

if it is such a horrible spell then Hogwarts would have some kind of protection against doing it inside the walls just like no apperating. wouldn't they?

who did he kill to split the soul (he didn't actually kill Myrtle the basilik did)
I wonder if that counts but even if it did

Myrtle was dead at least a while before Tom framed Hagrid. the trophy wouldn't even have been in existance when Myrtle died. I don't remember any other mysterious deaths being talked about during his time at Hogwarts.

I would assume that the object you want to use as a Horcrux would have to be with you at the time of the murder so that you could put the soul inside the object right away. You can't just run around with a piece of your soul in your pocket!

I don't know enough about Horcruxes to make a good judgement on this one. These are just some questions I have in regards to the theory that the award is a Horcrux.