El Pais newspaper reporting that several banks are a leetle bit in need of more capital....
might be the reason for plunge just before 4pm...
link to an interesting translation (via Google translate) here:
http://translate.google.com.au/translate?hl=en&sl=es&u=http://www.elpais.com/&ei=GTJJTJ2fDYqWvAOo6MidBQ&sa=X&oi=translate&ct=result&resnum=1&ved=0CCYQ7gEwAA&prev=/search%3Fq%3Del%2Bpais%2Bnewspaper%26hl%3Den%26prmd%3Dn