If Guo's intention is to collect shares on the cheap, it is better for him to do it slowly as too fast a runup will see sellers holding back and other buyers coming in to compete against him, especially short sellers trying to cover. Once he has collected from all the weak holders, the shorts will be at his mercy.

You got it! This is because AMCN's trading volume is too small and Guo likes to grasp the shares with low prices. As I said before, he is good at trading stocks. Remember that we still have over 1.2 million shares in short!