I've seen them in both locations. I learned that if they are up top, they are ready to eat. Every fish my buddy boated, all sitting at the top and larger than all the fish I was pulling further down. This time of the year I caught 3 fish in a 100 yard stretch, 2 on top of two different steak beds and one on the bottom under a limb. There was no temp change this all took place in less than 30 mins. If you have Live Scope and see a bulge up top, it's probably a slab waiting to get caught.