I often visit my profile to make quick investigation of my account, and sometimes i see there Loss in Reputation like,
loss but i only get that information from tabs, Reputation graph doesn't show me how much reputation I've lost, It only shows Reputation Gain.
I believe most of users only go for Quick Analysis by Reputation graph of their Profile page.
It will be good, If the Reputation graph of profile summary shows not only Gain in Reputation but also the loss in Reputation.
Proposed Design for Reputation Graph on profile summary page: