Q: What does the status "Decision in progress" mean?
I have submitted my research article to a journal in June 2019. The status was "Under review" for 4 months, after which, on October 8, it changed to "Decision in progress." What does this statement mean? Will my paper rejected?
You have not mentioned whether there were any other statuses before "Under review," so it's difficult to say if this is the internal editorial check or the external peer review. If the status changed to "Under review" directly after submission without any interim changes, it is likely to be the initial editorial screening. If that is the case, the status "Decision in progress" might be indicative of a rejection. However, if the "Under review" referred to the external peer review, you can be hopeful. Whatever it is, you should be informed of the decision soon.
All the best!