Credit Suisse will borrow up to nearly $54 billion from Swiss central bank in bid to calm fears

Credit Suisse's shares soared as much 30% on Thursday after it announced it will move to shore up its finances by borrowing up to nearly $54 billion from the Swiss central bank, bolstering confidence as fears about the banking system moved from the U.S. to Europe.

It was a massive swing from a day earlier, when shares of Switzerland's second-largest commercial bank plunged 30% on the SIX stock exchange after its biggest shareholder said it would not put more money into Credit Suisse.

That dragged down other European banks after the collapse of some U.S. banks stirred fears about the health of global banks. European bank shares recovered a bit Thursday, with the Euro Stoxx Banks index of 21 leading lenders up 1.6%, following a steep 8.4% drop Wednesday. Bank stalwarts like Commerzbank, Santander, Unicredit and Raiffaisen all rose more than 2%.