Noticed my score was credited -1 due to downvote. Funny thing the record references the topic which I didn't ask and never answered. Bug or something?
Topic: Splitting a large table
The -1 would be associated with a downvote you cast on someone else's answer. From that link:
What happens when I vote down?
When you vote down, you are nudging that content "down" the page, so it will be seen by fewer people. Voting down answers is not something we want you to take lightly, so it is not free.
If you want to check your complete reputation calculation, see your personal reputation report.