CCME The six month thing is a red herring. If the shares were purchased in the open market, this may be insider trading (although rato makes a very good point -- the forthcoming dividend policy had been disclosed -- it's just that nobody believed them because, well, it's Chinese). If they were purchased privately from a seller who also knew about the forthcoming dividend policy, then it is not insider trading.
If the stock climbs to $18 today, Jacky's profit is $300k. Is it worth chasing? I really don't see the SEC jumping into this -- there is so much more egregious conduct in this space that it would see odd to go after this company, which has otherwise done everything right.