TAS/EDE relative values, page-874

I came over here as a none holder to discuss the T/E relative value. Trying to better understand. I may make assumptions which my sound negative or they are expressed poorly but bear with me.

Today the prices EDE 0.065 v Tas 0.051 as such here is a 0.014 gap between the two share prices.

Now EDE and TAS are both tracking the fortunes of EDE and Edencrete, in a vacuum that would mean that the should move in step. So as time goes on a net increase in share price will mean that as the 0.014 gap remains the same so the Relative Value decreases. Conversely as the price goes down and the 0.014 gap remains the same the Relative Value increases.

Given that the price gap would stay the same based on both company's share holders reacting similarly to news, what introduces a increase or decrease of that gap? Is it merely an overall different prospective on the news, is it the TAS only news - say on some of the resource side of the business? Or is it artificially impacted by the arbitrary decisions of those who trade on any particular day.

My opinion is that there is more of a phycological influence then a physical measurement.