Spread over Treasuries
The yield difference between a bond and US government debt of comparable maturity.
How to read the number
It separates the payment for a specific borrower's risk from the general level of world rates: the level can rise while the payment for risk falls.
When the metric lies
The spread also widens with nothing wrong at the issuer — when safety itself gets more expensive, that is, when demand for Treasuries jumps.
Also known as: credit spread over treasuries