Still, Zions could offer a buying opportunity for risk-tolerant investors. Zions shares have dropped 55% in the past year, closing at $13.46 on Tuesday, which is 64% of its tangible book value, according to SNL Financial. Many analysts expect regional holding companies to fall prey to stronger competitors through acquisitions. The companies most likely to survive will have stable funding sources and solid deposit growth. -- Reported by Philip van Doorn in Jupiter, Fla.