For nearly six years running, the U.S. stock market has withstood a myriad of body blows, from a stuttering economic recovery to a debt crisis in Europe to massive political instability in Washington.
Underpinning each move higher was the knowledge that the Federal Reserve would keep the printing presses running, with aggressive quantitative easing programs that sent market confidence high and asset prices soaring.
Now, though, comes a shock that has Wall Street reeling: The Black Swan-like collapse in oil prices that has provided a stern test of whether equity markets can survive nearly free of Fed hand-holding.
So far, with volatility spiking, traditional correlations breaking down and the bad-news-is-good-news theme no longer in play, the early results are not particularly reassuring.
"Stuff happens when QE ends," said Peter Boockvar, chief market analyst at The Lindsey Group. "It's no coincidence that the market started going into a higher volatility mode, it's no coincidence that the decline in commodity prices accelerated, it's no coincidence that the yield curve started flattening when QE ended."