Silicon Valley Bank's shares have plummeted after the company announced it would be raising additional capital by selling stock and taking a charge to roll over an asset portfolio. The bank's CEO has assured clients that their assets are safe, but venture firms are advising portfolio companies to move money out of the bank. The bank's financial troubles are attributed to a mismatch in deposits and withdrawals, as well as pressure from the decline in venture capital investments and startup clients burning through cash. The bank's share price has fallen over 60% compared to last year.