Wary investors sank the markets with the Dow stumbling 138 points to 12,502 as few details emerged about bailout for Spanish banks. Nasdaq plummeted 56 points to 2836.

On the upside

Oaktree Capital acquired shares of GenOn Energy (NYSE: GEN) last quarter.

Shares of Horizon Pharma (Nasdaq: HZNP) continued rising after announcing last week an exclusive partnership with Grunenthal to commercialize Duexis in Latin America.

Bargain hunters lifted shares of Overland Storage (Nasdaq: OVRL) whose stock price tumbled last week after the International Trade Commission found no patent violations on the part of BDT.

On the downside

ChinaCast Education (Nasdaq: CAST) withdrew its appeal of Nasdaq's decision to delist the company from the exchange.

Shares of Key Energy (NYSE: KEG) continued falling after FBR Capital downgraded the company to a Market Perform rating last week.

Sonic Automotive (NYSE: SAH) announced a private offering of up to $200 million worth of senior subordinated notes.

In the broad market, declining issues outpaced advancers by a margin of nearly 7 to 2 on the NYSE and by nearly 3 to 1 on Nasdaq. The Russell 2000 which tracks small cap stocks tumbled 13 points 761.