• Use of special gem pouch verbs
• Able to tie gem pouches at any time
• Spooking pack animals to get out of danger
• Able to read and study ledgers.
• Access to Trader only housing and associated perks
• Able to send a posse after thieves caught stealing on the trade routes

• Commodities trading

• Interprovincial contracts
• Access to Trader guild shops

• Speculate Coin

• Dragging corpses with pack animals

• Able to sell gem pouches (this can vary from player to player)
• Access to banquet facilities (Riverhaven only currently)
• Speculate Finesse

• Trader Market
• Trader market certificates and discount coupons
• Extra appraisal information on some jewelry items (can vary)

• Horse trading

• Auctions

• Rent kregkeirels on Surlaenis with "portable vault"
• Able to store multiple horses
• Storage boxes for mainland caravans

• Market stalls (3 tables in your own stall for 10 days)

• Possibly speculate chaffer

• Trader financed gem shops and furriers

This is taken more or less verbatim from GM Godrich's site. Credit goes to him.