Don't top up mate, CYB is most exposed to the brexit it is already the most hit stock on the ASX today. CYB operates Clydesdale and Yorkshire banks, and gets 100% of its revenue in the UK. In my opinion this is the start of a long term decline for CYB.
"Among Australian-listed companies, CYBG (ASX:CYB) – the holding company which owns the Clydesdale and Yorkshire Bank in the UK has the largest UK exposure, according to the German bank".