What happens to your Freddie/Fannie stock if there is a Government "takeover"?

I have heard that, if there is a government "takeover" of Fannie Mae and Freddie Mac, stock value will be "wiped out"... now does this mean that I would completely "lose" this stock or does this mean that only the "current value" is gone? I want to be able to hold onto the stock anticipating a rebound.