$Credit Suisse Group AG(CS)$ Shares of Credit Suisse (CS), the beleaguered Swiss bank closed lower by 14% on Wednesday after it's biggest shareholder said they wouldn't be investing more money in the company. The chairman of Saudi National Bank, Ammar Al Khudairy, told Bloomberg Television the bank will not invest further in Credit Suisse due to regulatory concerns. His comments came the day after the bank revealed it found "material weakness" in its financial reporting. By late Wednesday, there was so much turmoil regarding Credit Suisse that Swiss National Bank, Switzerland's central bank, said it would provide the bank with liquidity if necessary.