I can see NO OTHER outcome other than that.
Call around to the 4 or 5 major brokerages, there just are no more MRKR shares available to borrow to short.
From here on out, any significant share price move upward should cause ("SOME"), (the lowest priced ones) to cover, which should amplify the upward stock price movement.
Unless after investing since the 1980's and being relatively successful at it, I am just crazy.