taultunleashed

When you are trading items to someone (especially stacks of items), you can trade up to 9 things to someone before clicking trade. Once all slot fill up, just click and drag more items up to 3 more stacks and they will all trade over once you click trade.

As far as i know that was nerfed a good 6 months ago.

Nope this still works... just drag on to the person... Its not much of an exploit though... pretty widely known

there are actualy UI mods designed to show all 9 trade slots. So if you want to call it an exploit, its hardly a cutting edge find.