(I) hope so
I would naturally expect that this would happen or be true. A: "My manager said you can get a refund on the item." B: "I hope so—it arrived broken in two pieces!"
(I) hope so.
a phrase expressing the desire and wish that something is so. Bill: Is this the right house? Bob: Hope so. John: Will you be coming to dinner Friday? Sue: Yes, I hope so.