If the stock market were a movie character, it would be the martini-swilling Broadway star Margo Channing (played by Bette Davis) in "All About Eve" who famously quipped: "Fasten your seat belts, it's going to be a bumpy ride."

"Bumpy" might be a gentle way to describe the current volatile market in which the Dow Jones industrial average swoons and falls in triple-digit increments with an alarming regularity. Today's culprit was an expectedly weak report from the Institute for Supply Management's non-manufacturing index, which measures the services economy. Worries that the index indicates a serious economic slowdown sent The Dow Jones Industrial Average down 234.76 points, or 1.86%, to 12,400.40. The NASDAQ Composite Index slumped 39.66, or 1.66%, to 2,343.19 and the S&P 500 dropped 26.25, or 1.9%, to 1,354.57.

According to The Wall Street Journal (subscription required), the non-manufacturing index was 41.9 compared with 54.4 in December, "far lower than the forecast 52.5. Any reading below 50 indicates contraction." Bloomberg News says the index contracted in January at the fastest rate since 2001. The Journal and the New York Times say the services sector contracted for the first time since 2003.

No wonder pundits were left speechless.