Has a Certain Magical Index Ended?

The anime went on a hiatus right after that and it wasn't until the end of 2018 when a new season of the anime, 'A Certain Magical Index' season 3, came out on October 5, 2018 and ended its run on April 5, 2019. We are quite positive that the anime will be renewed for another season.

Is A Certain Magical Index novel finished?

The game was updated to A Certain Magical Index: Struggle Battle II, but was later announced the end of its service on March 30, 2018.

Will there be A Certain Magical Index Season 4?

A Certain Magical Index Season 4 Isn't Confirmed

There was, however, a lengthy gap of almost a decade between the release of the second and third seasons of the anime, so the lack of confirmation as of yet doesn't necessarily mean the series is done.