hard work
you unlikely buy stuff like that just one day before it goes up - you stand through the hard times and then - maybe - reward comes...
Specifically, I bought this one many moons ago - I was impressed with how management pushes the company through difficult asbestos challenges + nobody seemed to be appreciating it judging by very low PE (of course except of important exception of Buffet). USG is big in what they are doing, i.e. they have a pricing power and will weather any housing slowdown. Likely they will emerge only stronger.
This is kind of stock you ramp up even when it goes down....sometimes if you are scared it helps to buy calls instead.