Auctions are lots of treasure that characters can create and bid on. To start an auction, go to your character sheet's treasure page, click the item you want to auction, and then click the Auction button.
Crystal of Hypnosis
Spell "Gaze Sleep" on Spell Focus
Infusion of Displacement
Immune Burst on Outfit, Shield, or Trinket
Infusion of Heartless Opportunist
Crit vs. Compelled on Melee Weapon, Projectile Weapon, Spell Focus, or Wraps