You are given the following default-free long bond:
Face value: 100
Issuing price: 100
Currency: USD
Maturity: 30 years
Coupon: 6%
No implicit calls or puts. Further, in this market there are no bid-ask spreads and no trading commissions. Finally, the yield curve is flat and moves only parallel to itself.There is, however, a futures contract on the 1-year Libor rate. The price of the contract is determined as
Vt= 100(1-ft)
where ftis the “forward rate” on 1-year Libor.
(a) Show that if the yield of the 30-year bond is yt, then at all times we have
yt= ft
(b) Plot the pricing functions for Vtand the bond.
(c) Suppose the current yield y0is at 7%. Put together a zero-cost portfolio that is delta-neutral toward movements of the yield curve.
(d) Consider the following yield movements over 1-year periods:
9%7%9%7%9%7%
What are the convexity gains during this period? (e) What other costs are there?