hello T333 bramble
What ive noticed about £ and E against $ is the difference between their prices changes.
ie (£$ pip value - E$ pip value) = difference
at least from 96 - 00 using weekly opening prices this value fluctuated (approximately) between 4000 / 6000 pips. This range could be traded by taking opposite positions in each pair.
ie when difference = 4000 pips you would go long £ and short E in equal pip value and aim to close the position when the difference is nearer 6000 pips..
ive looked at 1 hour data over a period of 1 month but the results more often where quite poor (many of the months results seemed to trend).
Of course the perfect scenario would be 'a pair' that ranged well over time, it would akin to buying and selling a value of a ranged indicator..
BTW this is something ive noticed and followed up so sorry if this isnt pair trading etc as such