abbott is in, carbon tax is out, page-11

In your terms, things could have gone either way, and the way they went means you just lost some jam. That makes more than zero difference.

Yep, sometimes things are uncertain. In those cases a value is priced in based on the values of the up and down sides and the probability of each. When things are confirmed the realised value is either greater or lesser than before confirmation. If you drill a well and it's a gusher the price goes up, if it's a duster the price goes down. You seem to think everything should be valued at zero until you have confirmation. On that basis AEB would be massively overvalued at 5c.