Shares of European banks tumbled on Thursday, resuming a downward run that has knocked more than one-quarter off their value this year.
Analysts are divided as to what markets are more scared by — the still-sluggish euro zone economy, exposure to the energy sector and China or some banks' balance sheets?
On Thursday, the head of Societe Generale was the latest bank executive to attempt to reassure investors that there was nothing to fear.
"There is too much nervousness compared with reality… The quality of the banking sector is much better than in 2008," Frederic Oudea told CNBC, as shares of his bank slumped following results that missed expectations.
With that in mind, CNBC takes a look at some of Europe's largest banks by market capitalization and what, if anything, you need to worry about.