Petroleo Brasileiro Petrobras SA (NYSE:PBR) was the recipient of a significant drop in short interest during the month of November. As of November 14th, there was short interest totalling 88,765,318 shares, a drop of 5.1% from the October 31st total of 93,559,567 shares, StockRatingsNetwork.com reports. Petroleo Brasileiro Petrobras SA (ADR) (NYSE:PBR) belongs to Basic Materials sector. Its net profit margin is 6.20% and weekly performance … Continue reading Notable Ups And Down: Petroleo Brasileiro Petrobras SA (ADR) (NYSE:PBR), Schlumberger Limited (NYSE:SLB), Ophthotech Corporation (NASDAQ:OPHT), Royal Dutch Shell (NYSE:RDS-A), Citigroup (NYSE:C)