"there are so many events that can can cause a price surge and almost none that can cause a further contraction."
To make a statement like that indicates you are not thinking.
What recently caused oil to drop from $100+ to $50? All the same bulls (you) that bought Peewee during the accounting debacle and price drop never saw it coming.
What caused the price to drop in the mid-1980's and stay depressed (=
Can't even buy a cup of coffee with what a share is worth now.