Spanish bank CaixaBank, which is headquartered in Barcelona, was down 6.7 percent on October 4th, according to infobolsa.es, which monitors the share value of Spain's leading companies. Banco Sabadell, Spain's 5th largest bank, also lost 6.3 percent of its share price.
Both credit institutions are headquartered in Catalunya and face a potentially uncertain future as Catalan President Carles Puigdemont said he would declare independence from Spain by early next week following the October 1 referendum.
CaixaBank said it would take all decisions "to protect the interests of its clients, shareholders and staff," according to an internal communication allegedly seen by El Pais, although it stopped short of suggesting it could relocate.
Most Spanish banks were trading far below average on the morning of October 4th, reports El Pais. Santander lost 3.2 percent, while major national banks Bankia, Bankinter and BBVA all lost between 2 and 4 percent of their share price as the unrest continues in Catalunya.
The European Central Bank has also expressed its concern about the referendum's impact on Spanish credit houses, according to a report in Spanish daily El Confidencial.
"Investors want tranquility but we are living a situation of uncertainty in which there is no guarantee of calm," analyst Joaquín Robles told La Voz de Galicia daily.
Spain's finance minister meanwhile, Luis de Guindos, was keen to emphasize how the EU has defeated populist movements in a tweet on October 2nd, following a meeting with his Italian counterpart.
"Europe grows, it has been capable of defeating populism and pro-European sentiment prevails," tweeted de Guindos on October 2nd.