Further proof that every field has its own nerdy inside jokes:

Yesterday a colleague at the investment firm where I work was telling me about how she'd set up one our co-workers with a friend of hers, and how they were going to have their first date that night. We then had the following exchange:

She: I'd say I did a pretty good job of brokering that trade.
Me: Yeah, well, these days I'm still trading as a principal for my own account.

We both found this quite amusing.