UBSS is a MM. If they sell at "market" instead of limit, the other MM's will then quickly move lower to take those "foolish" shares away. This has been going on for a while. Some of us suspect that LS estate may be doing it, but NO proof. Could just be traders doing the same in panic.
I wrestled with reality for years, Doctor, and I'm happy to state, I finally won out over it. (Jimmy Stewart in "Harvey" 1950)