I think this needs a nice drop, before heading into the Christmas rally.
This recent bounce by the GBPUSD, is certainly not helping the FTSE 100. Now, I strongly recommend to watch the Pound/US Dollar pair, because it will definitely show the direction for this UK index.
Currently aiming for it to touch the trend line and then, if we're lucky, the break of it. Of course, recent fluctuations around Brexit and other stuff, might stir it up a little. If you like the idea of a SHORT, then have a nice STOP.