Violent protests in Greece weighed the markets down to a lower close with the Dow easing 3 points to 18,050. Nasdaq slipped 5 points to 5,098.

On the upside

Shares of Ohr Pharmaceutical (Nasdaq: OHRP) soared again.

BG Medicine (Nasdaq: BGMD) paid off its secured term loan facility.
 
JP Morgan upgraded PTC Therapeutics (Nasdaq: PTCT) from a Neutral rating to an Overweight rating.
 
On the downside

Retreating crude oil prices weighed down shares of Magnum Hunter Resources (NYSE: MHR).

Imperial Capital downgraded Penn Virginia (NYSE: PVA) from an Outperform rating to an In-Line rating.

Marten Transport (Nasdaq: MRTN) reported higher second quarter earnings but the results fell short of analyst expectations.

In the broad market, declining issues outpaced advancers by a margin of nearly 5 to 3 on the NYSE and by nearly 2 to 1 on Nasdaq. The broader S&P 500 slipped a point to 2107. Bitcoin held steady at $287.