How did the rerate/buyout(?) effect SP?

Hey folks, here with a bit of an old question and I recall the answer but if someone whos much more knowledgable than me explain it that'd be sweet.

So when it went from 40c to $2.60 I understyand the GXY share was aportion of that 2.60? So if you have GXY the vlaue didnt go from 40 to 260 but was kind of absorbed? At this point in time when it keeps going does that maintain? How does it show up in your portfolio? What do you cash out at? Does it grow proportionately?

Any clarity of this will be great for a noob like me to wrap his head around as this was the first time seeing something like this.

Muchos Gracias!