Is all karma* always bad? Stated differently, can the concept of karma ever denote good, or does it always mean bad?

*Of course, while anyone at all may answer if he or she wishes to, there is the understanding that not everyone believes in karma, or believes in it in equal measures, or believes in its definition/definitions in equal ways.  Some people do not believe it exists at all, and there is absolutely nothing wrong with each person making an independent determination on it. Not all of us have to think the same way.

Thank you all in advance.