Concerns of a tepid earnings season sent the markets tumbling during the midday with the Dow plunging 117 points to 16,295. Nasdaq plummeted 46 points to 4081.

On the upside

Idenix (Nasdaq: IDIX) reported continued progress of its nucleotide prodrug development program to treat hepatitis C infection.

Agios Pharmaceuticals (Nasdaq: AGIO) reported promising clinical data of its AG-221 IDH2 mutation inhibitor.

Bargain hunters lifted shares of Petroleo Brasileiro Petrobas (NYSE: PBR).

On the downside

Sears Holdings (Nasdaq: SHLD) completed the separation of Lands' End.

Shares of GTX (Nasdaq: GTXI) extended its losses from Friday when it announced the departure of chief executive officer and co-founder Mitchell S Steiner.

Rite Aid (NYSE: RAD) named David Abelman to the position of senior vice president of brand development and innovation but the stock price fell.

In the broad market, declining issues outpaced advancers by a margin of nearly 5 to 2 on the NYSE and by nearly 7 to 2 on Nasdaq. The broader S&P 500 tumbled 15 points to 1849. Bitcoin lost $18.70 or 4.06% to $442.19.