Typical whale moves. Whales tend to dump on positive news before a positive market response is expected (like from the announcement of the dev) people new to the market question themselves when they see the price dropping "hey I thought the news was good, I must be wrong, I'd better sell"
This mild panic allows the whales to buy more at a cheaper price. Best strategy is check the fundamentals which are solid and either hold or join the cheap buy in.
I am not saying the entire market is being controlled by a few whales, but at these prices and at the current market cap it is easier to manipulate the market. Once the XC market matures a little these antics will be harder to perform. Keep an eye on the rich list, the top 100 will accumulate where the people with less XC will sell more.
Put trust in your investment, the business plan of XC is rock solid. There has not been any bad news or hiccups that should have any negative influence on the price of XC. The price volatility is caused by emotion. Cancel out emotion when trading, base decisions on facts and you will do good.
Stand fast