There were a series of news before investors started panicking, it’s not like people randomly decided to dump the stock without any reason.
> (March 9) Credit Suisse shares drop as annual report delayed following SEC call
> Postponement comes as regulator weighs in on 2019 cash flow statements
> (March 14) Credit Suisse finds ‘material weaknesses’ in financial reporting controls
> Swiss bank says it lacked effective processes to identify risk of misstatements
Yeah. No restatement to the numbers already published. Doesn't look good but should hardly move the stock price, let alone the credit worthyness (two distinct things).
> (March 9) Credit Suisse shares drop as annual report delayed following SEC call > Postponement comes as regulator weighs in on 2019 cash flow statements
> (March 14) Credit Suisse finds ‘material weaknesses’ in financial reporting controls > Swiss bank says it lacked effective processes to identify risk of misstatements