Chaince is the first, and currently only place to trade EOS assets, which many EOS holders received as airdrops. Currently available for trading are CET, Chaince's own token, IQ and OCT. RAM trading is also available (which is great as it's the only service currently offering a buy/sell order system), as well as EOS/BTC and EOS/ETH pairs. There are still assets to be added, for which the market is excitingly anticipating.
So if you want to pioneer EOS's assets trading, fill out their KYC requirements and get to business.
Cheers!