I have recently restarted the game as a different character and I cannot remember who to talk to/what to do in order to get the Trademeet Quest to trigger. I want to complete this one before D'Arnise, Windspear, etc. Help appreciated...

someone in the bridge district I think.

Sorry I thought the gate was in the bridge district.

A man standing in the gate area...I believe he is crying out for help.

Nemthan:

Each time I've been approached for that quest it has been at the city gates, I believe. Talk to anyone nearby after you arrive in the map area.

Cloudbringer

Well, the Trigger is a young boy who walks up to your party and starts talking to you (or Minsc most often) and sets off the Trademeet quest.

Well, the Trigger is a young boy who walks up to your party and starts talking to you (or Minsc most often) and sets off the Trademeet quest. He seems to come at a certain time, where ever you are (only in the city), not in a certain place (I've met him in the government and Bridge districts on different play throughs).

Wrong quest Demus, that's for the Umar Hills quest. Tradesmeet is given to you by a guy in the City Gates district.