Pros
Challenges. If you like to be challenged, there's many opportunities. Start a project, then half way through it 'poof' the people you were working with are gone, typically replaced by inexperienced Indian speaking low paid H1B candidates. Salary is ok, but don't expect too much in the way of a raise.
Cons
Executive Management is a revolving door. Fidelity is the place where 'executives' like to end their days getting highly paid to put their 'stamp' on the company. Almost like clockwork, every 5 years or so, executive management changes. Then the newest group of executives start their own slash & burn program to make the company more 'productive'. Once they've finished this wonderful task and decimated the various groups they declare victory, collect their huge bonuses, and turn things over to the next group of bean counters. Fidelity is coming apart at the seams because there are so many chiefs and so few indians left to any real work.