Because the deal is bad and the Market makers are taking it to 14 or below where it belongs. Several huge sellers want out badly, that is why every single time you see green, it is followed by weakness in general and dumping.
Yoku trades so weak, just like most the China stocks lately as China is really slowing as #'s and news releases prove weekly.
When the chinese stocks are acting this weak and the S and P is only 2% off the highs, you would be crazy to be buying any of the chinese stocks before they make 52 week lows, (they are all going in that direction. Sina has been extremely weak, even on up days, yoku just makes baghoolders almost always the same day, that they made that first long buy.