The volatile markets turned negative during the midday with the Dow dropping 69 points to 15,052 over renewed concerns about the global economy. Nasdaq tumbled 24 points to 3412.
On the upside
Shares of Gigamon (NYSE: GIMO) surged in its market debut.
Hedge fund Glenview Capital requested that Health Management Associates (NYSE: HMA) increase the maximum stake that a single shareholder could have in the company from 15% to at least 25%.
Amgen (Nasdaq: AMGN) and Cytokinetics (Nasdaq: CYTK) expanded their development and marketing partnership for the heart failure treatment omecamtiv mecarbil to include Japan.
On the downside
GenMark Diagnostics (Nasdaq: GNMK) extended its losses.
Citi analyst Yaron Werber downgraded Biogen Idec (Nasdaq: BIIB) to a Neutral rating from a Buy rating.
LDK Solar (NYSE: LDK) stock continued falling after reporting a greater loss for the first quarter yesterday.
In the broad market, declining issues outpaced advancers by a margin of 5 to 2 on the NYSE and by nearly 2 to 1 on Nasdaq. The broader S&P 500 index fell 9 points to 1616.