I do not know what happened and what's more is that the price of BCD varies significantly from exchange to exchange. Just this week I lost 1000 bucks on BCD that I had bought in Gate.iom and the price plummeted to 15 dollars, while in Kucoin and Yobit it was around 50, what is worse is that none of these exchanges allow you to transfer BCD. All this because apparently no one knows who is behind BCD, then again we have the same thing with Bitcoin. But people will be people.
Yeah cryptocurrencies often vary greatly in price across exchanges.
The trend with these forks (after BCH) has been falling prices after their debut, but Bitcoin Gold has since stabilised recently.
So i think it's best to hold off for a good while before considering buying any, especially since like you say, there's still question marks about BCD, and several others.