First day of the quarter a "sell the gainers" event: major sectors show perfect inverse image of Q1 performance.
Not surprisingly, industrials and materials are notably weak. You have a double whammy of below-expectation ISM manufacturing data in the U.S. and it's counterpart, China, is also a little short. And, of course, we are in recession territory for manufacturing indices in Europe.
Little wonder that copper futures are breaking to a nearly eight-month low...and that metal stocks across the board (aluminum, steel, iron ore, copper, and coal) are down three percent or more.
Tech is also weak: Micron Technology (MU) is down four percent, leading chip stocks lower.
One of the survey respondents to the ISM manufacturing survey, who works in computer and electronic products, summed up the sentiment by saying that that "second half of 2013 looks promising, the first half is a mixed bag."
If today's declines hold, it would be the first time since Q4 2011 that the S&P 500 has been down on the first trading day of a quarter (thank you, Robert Hum).
—By CNBC's Bob Pisani