The similarity lies in that this kind of event also adopts an invitation-by-token system, where only those holding a token can enter, and participants are encouraged to conceal their identities.
At the same time, the origin of any item that appears at the Underground Treasure Exchange Convention is not to be inquired into.
The difference lies in the location and revenue structure of the Underground Treasure Exchange Convention.
Generally, the Underground Treasure Exchange Convention is held in the safe confines of a marketplace, so even if someone exchanges something valuable at the Convention, they need not worry about being ambushed and can take their time to deal with the item within the marketplace.
At the same time, the organizers of the Underground Treasure Exchange Convention will charge the seller a venue fee for successful transactions, usually amounting to around two percent of the total value of the items sold.