'Castles built on sand': Famed economist David Rosenberg says investors are being too reckless as stocks rally — and warns that a vicious long-term bear market is far from over

· David Rosenberg — the famed economist and founder of Rosenberg Research —  thinks investors are putting too much blind faith in the Federal Reserve's ability to prop up a "frothy" market.
· In addition to a perceived Fed-backstop, Rosenberg notes weak market fundamentals and lofty valuations as reasons for his...