Wow! That was a very fast transition from the initial announcement to excess bid? Why is it I get the feeling we aren't being told everything that's known?
-1 means they can excess from that seat to balance people moving(relieve to excess) in. You can bid to where your seniority holds(foreign domiciles have a restriction that one can excess to it as long as it doesn't cause an excess in that domicile.
This excess is going to look extremely doom and gloom. Everyone from HKG will have to excess back (on paper) causing a bunch of movement prior to the vacancy bid opening up.