Need Advice on a Stock Term

Lets say a company is $16

Then they restructure

Now those same shares worth $6

For example the stock G — E — V — O

Its $2 now

But in 2011 it was $150,000,000

I looked into it more and it was never that price at the time it was $15 but then did something.

1. What is that called?
2. Does this usually happen when a company is in constant decline?
3. Can this happen to a company on the rise?

Please do give examples