Q: What does a status change from required reviews completed back to editor assigned indicate?

I've submitted my paper to a Springer journal. For the first week of submission, the status was "with editor" and then it changed to under review for one week. For the next two days, reviewers were assigned and then the status again changed to under review for 10 days, and then finally to "required reviews completed". The status "required reviews completed" was shown for one week and then it changed once more to with editor again. It has been this way for the last 10 days. Now my question is if rejection is the verdict, wouldn't the editor immediately send the rejection letter? Why is the editor taking so much time to decide? Is it a good sign or a bad one??