Bank stocks gave back a chunk of their gains. The KBW Bank Index is down nearly 14% from its August high.

We had a nice run for over a year. Now we're seeing some mean reversion. This is what banks do—they rally hard when sentiment shifts, then they give some back when reality sets in.

Nothing moves in a straight line. The question isn't whether they pulled back. It's whether the thesis that drove them up still holds.