Credit Suisse shares plunged to a record low amidst fears of a new banking crisis, as investors worried about the viability of the "too big to fail" Swiss bank.
The collapse of Silicon Valley Bank in the US over the weekend exacerbated concerns about Credit Suisse's future, with some experts fearing another "2008-style crisis".
Saudi National Bank, one of Credit Suisse's top investors, said it was unable to put in any more cash, exacerbating fears for the bank's future.
The Bank of England held emergency talks with Credit Suisse's international counterparts after its shares plunged as much as 30%, leading to concerns that central banks may have to start cutting interest rates.
The drop in Credit Suisse's share price - by as much as a quarter - has caused billions to be wiped off the value of top firms, with the London Stock Exchange's FTSE 100 falling 3.8% to its lowest level this year.
The US Treasury is monitoring the situation, and some analysts predict that if Credit Suisse were to fail, it could have major implications for other European banks that have exposure to the Swiss lender.
However, Credit Suisse has tried to reassure investors with the announcement that it will take a loan worth up to £44 billion from the Swiss central bank, describing this as "decisive action" to "deliver value to our clients and other stakeholders".