The markets stumbled during the midday with the Dow plummeting 141 points to 14,657 as Goldman Sachs downgraded the growth forecast for China's economy. Nasdaq plunged 43 points to 3313.
On the upside
Keynote Systems (Nasdaq: KEYN) will be taken private by Thoma Bravo for a premium of approximately $369 million in cash.
Bargain hunters lifted shares of OCZ Technology Group (Nasdaq: OCZ).
BB&T Capital upgraded Chiquita Brands (NYSE: CQB) from a Hold rating to a Buy rating.
On the downside
Solazyme (Nasdaq: SZYM) will dissolve its joint venture with Roquette Nutritionals.
Profit taking sank shares of YY (Nasdaq: YY).
In the broad market, declining issues outpaced advancers by a margin of nearly 9 to 1 on the NYSE by more than 7 to 2 on Nasdaq. The broader S&P 500 index sank 20 points to 1571.