People think trading is just as simple as it sounds but it's not. Because this leads to having to make items Soulbound and Bind on Pick Up/Bind on Equip. If there is trading, there won't be trading of Legendaries. Unless, obtained through rare means. Though this gear wouldn't be equivalent to Raid gear due to it's drop. That's a broken game right there. That allows players to get ahead when not earned. So, Legendaries would fall in the category of Soulbound/Bind on Pick Up, unless dropped via world drop. Boss loot would be strictly Soulbound/BoP. Where as Blue or below would be BoE unless obtained from a Strike Reward or Quest/Mission. Exotics would strictly not trade-able because they are unique. Items like Ascendents (despite legendary quality), Strange Coins, Motes, and other forms of currency along with items that produce extra Glimmer would most likely be free game for trade. Could also go as far as to say Engrams could be traded. In my eyes, trading is a system that works for other games, but not this game.