It should show some bubbles on the top and sides, and the edge of the dough where it meets the bowl should be slightly domed, which indicates strength.
At the end of bulk fermentation, your dough should have risen anywhere between 20% and 50%. It should show some bubbles on the top and sides, and the edge of the dough where it meets the bowl should be slightly domed, which indicates strength. In the photo above, you can see all these signs. If you don’t see these signs, leave it for another 15 minutes in bulk fermentation and check again.