To trade can have two meanings in GuildWars:
Trade with an NPC Trader
In all cities you can find Traders for various goods (runes, dye, materials, ...).
A trader, unlike a merchant or a crafter, does not sell and buy goods at a fixed price, but depending on supply and demand. You may even find a trader "out of stock" if there is very little supply.
Prices have a lower limit (the same price that you would get if you sell the same good to a merchant, but are open end).
Trade with another Player
If you click another human player while in an outpost or city the "Trade" button will appear next to his name in your target monitor. Clicking that button will start a trading session.
During a trading session you can offer gold or any item you have in your inventory. You submit the offer and the other player will send back his or her offer in gold or items. Both sides can modify and re-submit their offers until they both accept the deal or cancel the trade session.
Beware of scammers while trading with other players!
Trade Channel
The trade channel is a chat channel where most players attempt to sell their items to other players, or attempt to buy items from other players. Words spoken in the trade channel appear pinkish-red in the chat window. Common abbreviations for the trade channel include:
- WTS = Want to sell
- WTB = Want to buy
- WTT = Want to trade
- Req = Requirement (as in attribute requirement for weapons or armor)
- ^ = Above (i.e. Damage +15%^50 refers to extra damage when health is above 50%)