When the PPS dropped below $15 yesterday it was clear to me that the MMs will try to close the gap, which they later did. After they closed the gap @ $14.56 the PPS went a little lower and then it went up again to $15.40. I am sure many big boys thought that after closing the gap it would be safe to put a stop loss order near the bottom. But the MMs can see all SL orders, and because they (or their clients) are still short ~2.3M shares (as of 10/31/2018) and now there were SL orders for hundreds of thousands of COOP shares at ~$14.50 they took the PPS down again with 100 trades within a few minutes to sCOOP up the shares.