Having constructed this, thought I might post an update for interest.

Possibly, the commercials have a fairly low short;long ratio at present, which might have a ceiling of 4.5:1 (green peaks). They've found this low level in part by increasing their longs to record levels.

Perhaps, they have room to allow to run upwards, with the possibility of adding shorts up to 475-500k+ (red dumb bell or beyond).

Perhaps, at some point they have two tipping mechanisms, increase the shorts of course, but then remove some of the longs ~ their ratio of shorts:longs increased right through last Nov/Dec tipping process.

2010 records - highest long position; highest minimum short position; less overhead room than ever to manouver by increasing short positions, unless they go to record size shorts.

24/11/2009 - highest weekly short position

perhaps