I've come to learn that from time to time large blocks are posted either on the buy or sell side with no intention of actually consummating the trade. It can be construed as a means to keep a lid on any share price increase (if posted on the sell) or a means to create "artificial demand" if posted on the buy side.
Considering that Cope's comments and rumours seem to indicate that a takeover may be coming soon, if I was a prospective buyer who has slowly accumulated a position, I would be inclined to have my broker post blocks on the sell side to trigger others to "panic sell" the stock down. They could then come in and scoop some cheaper shares. IMHO, a stock that is not a huge volume trader like OK would be is to manage in this manner.
If in fact a lid is being placed on OK, it can only be done for so long.