Petroleo Brasileiro Petrobras SA (ADR) (NYSE:PBR) stock rose 0.7% yesterday and closed in the green for the second consecutive day. The stock increased despite receiving a downgrade from UBS AG (NYSE:UBS) and Morgan Stanley (NYSE:MS). The downgrade came on the back of expectations for a large write-off in the asset value from Petrobras. This implies that the stock might have reached its bottom.