Credit Suisse's stock dropped to a record low after its largest shareholder, Saudi National Bank, announced it would not be increasing its investments in the company. This news caused a sell-off in the markets, with Credit Suisse's stock dropping by 25%, and Bank of America's stock trading about 3% lower. Saudi National Bank representatives cited regulatory concerns as the reason for their decision, and investors are now watching to see how the markets will react in the coming days.