GUEST COMMENT: I had a bad internal networking experience
Everyone tells you to network in this market, but I would like to offer a few words of caution. In my experience, networking can go badly wrong.
A few years ago, I was working as a contractor with a middle office department. I speak fluent French and was responsible for covering deals originated by the French sales desk.
Within a few months I developed a good relationship with a director and two VP's on the desk, and they told me that they really could use an Associate to help them out. One of the VPs, a direct supervisor, thought I'd be perfect for the role.
I sent the director an email and he discussed it with the desk MD. They both thought it was a good idea, but due to headcount/budget restrictions they didn't want to hire me directly. Instead, they decided to ask my department head if I could be seconded to the desk for a few months (of course they did this by forwarding my original email).
When my boss received the email he wanted to terminate my contract immediately (and he would have if not for the intervention my supervisor).
This just shows how careful you have to be. I was a contractor, free to move at any time, I wasn't being secretive (my supervisor encouraged me to apply) and the position was within the same bank. But departmental politics and my apparent "disloyalty" (remember I was a contractor working for rolling 3 month contracts with an immediate notice period) was enough to get me sacked on the spot.
We're always encouraged to network and to tap into the 'unlisted' job market but in a world as small as investment banking, there's a serious chance that an unsolicited approach to another department or rival bank can get back to your boss and leave you marked as disloyal or uncommitted.