Financial services stocks fell 5.5% at the open Monday, with Credit Suisse and UBS losing the slide lower.
Credit Suisse shares tanked 62% while UBS fell 14.5% by 8:28 a.m. London time after the latter agreed an emergency takeover of its embattled rival.
Other banks also lingered in the red, with ING Groep, Deutsche Bank and Commerzbank all down around 7% or more.
This article was originally published by CNBC.