COSS has profit sharing, which makes it a security. Secondly, the competition among exchanges is getting stiff and Bianance is already on track to launch a DEX, not to mention upcoming DEXes like NEX, which will be running on NEO. There are too many exchanges out there already and COSS seems to be late to the game.
My 2 Satoshi.
I agree with you in terms of coss being too late. I've held them for many months and finally came to the same conclusion which is why I've sold at a loss.