That's because they sold it with large market sells, stupidly. People also knew they were selling. I can't speak to OkEx, but at least two of the major top ten exchanges i'm reasonably confident have volume at least in the range of what they claim.
Yeah, but...then it isn't liquid. CEOs of big companies pre-announce stock sales all the time, and prices don't often move >5%. An announced sale of bitcoins shouldn't move the prices in a liquid market. It suggests a buyer/seller mismatch.
