The rule of thumb is that for each 1% increase in interest rates, a bond loses its years to maturity as a percentage.
So a bond with five years to maturity would lose 5%, and a bond with ten years to maturity would lose 10%.
If SVBs bonds had a ten year maturity when purchased, that's probably nine years remaining when interest rates increased from 1.5% to 5.0%, so that's 9 * 3.5 = 31.5% reduction in value.
If they bought $80 billion of these, that's a $25 billion dollar loss.
If their shareholders equity was $16 billion, then that's zeroed and a combination of depositors, the FDIC (for insured deposits) and other creditors would have to eat the remaining $9 billion.
So a bond with five years to maturity would lose 5%, and a bond with ten years to maturity would lose 10%.
If SVBs bonds had a ten year maturity when purchased, that's probably nine years remaining when interest rates increased from 1.5% to 5.0%, so that's 9 * 3.5 = 31.5% reduction in value.
If they bought $80 billion of these, that's a $25 billion dollar loss.
If their shareholders equity was $16 billion, then that's zeroed and a combination of depositors, the FDIC (for insured deposits) and other creditors would have to eat the remaining $9 billion.