The market horizon may be relatively sunny, but Goldman Sachs sees five key reasons to remain a worrywart.
"The basic market outlook that we forecast is one in which equities and bond yields can continue to rise together and in which developed market assets continue to offer better risk-reward than their emerging market counterparts," Goldman said in a note.
But it added "although the mood in markets has turned more optimistic, we still encounter nervousness about the capacity for the outlook to remain positive."
(Read more: Goldman most upbeat on Japan, Europe stocks in 2014)
The bank sees five key risks:
1. The most likely risk is that long-dated yields could rise more sharply than expected in developed countries.
While inflation remains benign and the major central banks still look committed to keeping unusually low policy rates for a long period, the "unusually low" risk premium between long-term and shorter-term rates suggests increased risks, it said.
"Periods where yields rise rapidly – even with strong growth – tend to hurt equities, as during the taper tantrum," over the May-to-September period when markets convulsed after the Federal Reserve first broached the idea that it would taper its asset purchases, it said. "If yields rise because of expectations of tighter monetary policy, this is more unambiguously negative for equity markets."