I've seen this type of trading activity many times before. Cleaning up a big block usually makes the stock jump afterwards or a serious shorter just keeps piling it on until the pounding on the $2 door, in our case, gives buyers sore knuckles and they back off for a while. Mackie could just be playing with this seller on their terms as neither of them knows what the real extent of the other's is. Using an anonymous give-up really sucks. It certainly is not full disclosure compared to when we buy or sell our shares.