How often do traders change desks/product groups?

I've seen people switching groups pretty easily at the analyst level - people with CMBS experience going to equity derivative structuring. At a junior level, it's not a big deal. Associate level, definitely possible but less common. It's at the VP above level when it's really hard.

a guy in my firm went from options market making to energy trading just like that, Depends on the person.

on a kind of similar note, how do guys go about looking to move to another firm without their current colleagues figuring out? Wall Street is a small place and I gotta think word gets out quick. Is it mainly via headhunters? Do competing firms commonly reach out to poach traders/sales ppl ?

Extrmeley individual specific, but in general gets harder as you go along. It gets harder and harder to switch the more senior you get to switch without taking a large downgrade in terms of seniority. But in the end its about who you know.

It's best to try internal transitions at junior levels or very senior levels. From senior associate to director, it's much harder to successfully transition internally.

The market is very difficult right now in terms of placements. I would look through a headhunter to find other opportunities. Poaching happens, but it's much much less common today than in 2006. There are just too many traders looking for work (supply) vs. diminishing demand.

As a junior entering sales/trading, I'd focus on picking up skills that are value-added/unique. Examples are building client relationships, ability to program/code etc. before trying a transition.

If you can trade options in one product, you can trade options in any product. Obviously there will be specifics that you need to learn, and the fundamentals will be different, but (as counter intuitive as it may seem) it's actually easier changing desks in a non-linear role.