A review of key market-based indicators shows that systemic risk is quite low, liquidity is abundant, and the economic outlook is reasonably healthy. This should inspire investors to take on more risk, and it makes a compelling case for the tapering and eventual reversal of the Fed's QE bond purchases.
Swap spreads in the U.S. are about as low as they have ever been. Conditions in the eurozone are not quite as healthy, but they have improved significantly in the past two years. eurozone 2-yr swap spreads are not too far above the 20-30 bps range that would be considered "normal" or "healthy."
This chart shows a longer-term view of the spreads on corporate bonds. It's the same message as CDS spreads: credit/default risk today is perceived by the market to be only marginally higher than it was during prior periods of healthy economic growth. Importantly, spreads continue to decline on the margin, suggesting improving economic conditions lie ahead.
The Vix index of implied volatility is currently trading in a "normal" range. There are no significant sources of concerns in today's market: the eurozone is doing better, China is still growing, the federal budget deficit has shrunk dramatically, the Fed has tapered and the sky has not fallen, and corporate profits remain very strong.
A contrarian might worry that this reflects complacency and that itself is a concern. It's always possible that some new fear-inducing event will pop up around the corner, but in the absence of major sources of risk, it is likely that the prices of risk assets will continue to move higher. Especially since the return on safe-haven cash and cash equivalents is very close to zero.