TLDR - Credit Suisse has been a sh*t show for over a decade. This has been coming for a while.
Credit Suisse is in investment banking and wealth management. It does not have a significant retail presence (EDIT - outside of Switzerland). Credit Suisse has also had a number of accounting, risk management, and other scandals over the last few years. They were bailed out late last year by a fund linked with Saudi Arabia who took a ~10% stake in the company. Today, they (the Saudi fund) refused to inject more capital and the shares have collapsed.
Credit Suisse is in investment banking and wealth management. It does not have a significant retail presence (EDIT - outside of Switzerland). Credit Suisse has also had a number of accounting, risk management, and other scandals over the last few years. They were bailed out late last year by a fund linked with Saudi Arabia who took a ~10% stake in the company. Today, they (the Saudi fund) refused to inject more capital and the shares have collapsed.