Sterling extends its slide on Thursday, reaching its lowest against the dollar in nearly a year at 1.2842, according to FactSet. Commerzbank describes sterling movements as "dangerous," warning its fall risks becoming "self-reinforcing." It notes the lack of an "obvious trigger" for Wednesday's sharp drop--albeit linked to concerns the U.K. could leave the European Union without agreeing a deal--which it describes as "worrying." If sterling develops "self-reinforcing tendencies" then expect "an acceleration of the downtrend," Commerzbank says. EUR/GBP trades flat at 0.9012, having reached a high of 0.9032 overnight, according to FactSet.