Given a single series of
nominal cash flows (like a riskless bond). If these payments are discounted to
net present value with a static treasury yield curve the sum of their values will tend to
[overestimate or underestimate?] the market price of the priced instrument. The
parallel shift, which, if applied to the yield curve makes the
NPV of the anticipated receipts equal to the market price is the
Yield curve spread (aka Z-spread).