Most of us reacted to the news with cautious/guarded 'optimism'. [=a feeling that something good may happen but will not definitely happen]
He maintains a sense of 'optimism', despite all that has happened.
The early sales reports are cause/reason/grounds for 'optimism'.
(..) How old are you? Seven, but I look a lot older. God bless you. He's seven! Now, this is a man with optimism in his heart! Belief in his soul! We are all children in the eyes of God! We are gonna get you out of that chair. (..)2008 The Curious Case of Benjamin Button