The Traders Guild HQ is the home of Longen and Yamdu in Trader's Edge. It should not be confused with another building in the same location, named Bank. The Bank is a vault or storehouse location, while the Traders Guild HQ is a Faction HQ.
If the player kills or imprisones Tengu and Longen while Tinfist is alive and free, the HQ will be turned into what looks like Tengu's Vault 2.0 and named "Prison".
If the player kills or imprisons Tengu, Longen and Tinfist, the Ancient Lab will be put for sale at 320 000 cats. It becomes the most expensive investment in the game, as Trader’s Edge turns to the Empire Peasants override.