Uncertainty

Uncertainty has the same effect as lack of confidence. Henry Blodget:

Believe it or not, the "stress tests" that the government is performing to see how that banks will do if the economy continues to get worse were originally intended to inspire confidence.

The government would subject the banks to all sorts of horrifying scenarios, the theory went, and it would then report that the banks had passed with flying colors--thus reassuring a nervous public that the financial system was sound.

Alas, from the beginning, the stress tests weren't stressful enough. The government then said it was planning to withhold the results of the stress test to avoid harming the bad banks--which defeated the whole purpose.