[mullingitover]

The market is currently valuing it on what it thinks other investors in the market will value it at.

It's a class in the Greater Fool Theory of investing, writ large.

[toomuchtodo]

What do you think it would take to create a cascading loss of confidence in the security?

[jimnotgym]

Time

[throwaway48476]

Time and bad results. That said the market can stay irrational longer than you can stay solvent.

[jimnotgym]

I think you are right. A minor shock in share price from a bad profit announcement will cause certain traders to have to sell to stop the loss getting worse, probably by an automated stop-loss order. This will start a chain reaction.