Will eventually come back up.
A game has shut down trading due to an exploit, and I know what you’re thinking. It’s not New World. It’s Diablo IV! Stay tuned another week or so for the next New World trade shutdown.
Anyway, a Diablo dev posted in the forums today to let people know trading has been suspended due to a dupe exploit allowing players to duplicate gold and items. Something Jesus might do. The announcement comes with the prerequisite warning that players caught duping things will be banned.
Duping is bad, don’t dupe.
We’ve suspended player trading in Diablo IV until further notice due to a gold and item duplication exploit. We are working on a fix to amend this issue and will update you once we’ve reinstated the ability to trade. Once that is done, we will continue to monitor this activity to ensure a healthy playing experience for all. As always, any account that engages in gold and item duplication exploits will be actioned in accordance with our End User License Agreement.
We thank you for reporting this exploit to us and your patience.
Source: Blizzard