Bond-market crash leaves big banks with $650 billion of unrealized losses as the ghost of SVB continues to haunt Wall Street

• Big banks are sitting on $650 billion of unrealized losses, Moody's has estimated.
• It's a sign even Wall Street's best-known names are feeling the heat from the Treasury-market rout.
• Crashing bond prices sank Silicon Valley Bank earlier this year, and there may be more chaos to come.

Crashing bond prices sank Silicon Valley Bank in March — and there's reason to believe that what triggered the California lender's collapse may be haunting Wall Street again.