Hi,i recently interviewed with a trading desk. Much of it went smooth, but the guys were really smart and immidiately realized when i was imprecise or simply bullshitting cause i had no clue how to answer their questions. Then they would focus exclusively on this topic and pull me apart like warm bread.

Completely legitimate but not too much fun for the interviewee. Now some of the guys gave me their business cards, some not. I understand that all of them work at the same desk and i basically talked to everybody.Now I'd like to give some sort of proactive feedback à la "thanks for inviting me and i know there lots of stuff i dont know, but i'd really work hard even in my freetime to learn that stuff". But should I? I don't want that to seem like a lame suck-up move. And I'm unsure whom of the guys i should email. All of them? just the 'highest ranking' guy? Should I even email at all?-CM