IMF Theory Chapter 1 Flashcards
3 compounding conventions
simple interest rule: A*(1+rt)
compounding interest:
- A*(1+r)^n
- A*(1+r/m)^k (k in {1,..,m})
- effective interest rate r’: A(1+r’)=A(1+r/m)^m iff r’=…
continuous compounding:
- Aexp(r)=lim A(1+r/m)^m as m–>inf
- multiple years: Ae^{rt}
Future value of cash flows (x_0,…,x_n)?
assuming t_i=i years
FV_n:=Sum( x_i*(1+r)^{n-i} ; i=0,…,n )
Present value of cash flows (x_0,…,x_n)?
assuming t_i=i years
PV_0:=Sum( x_i / (1+r)^i ; i=0,…,n )
IRR?
Internal rate of return is the rate lambda at which:
PV_0:=Sum( x_i / (1+lambda)^i ; i=0,…,n )=0 holds.
Under which conditions does a unique IRR exist?
- There exists k in {0,…,n-1} s.t.
- for every i in {0,…,k}, the x_i have the same sign,
- and for every i in {k+1,…,n} the x_i have the opposite sign.
- If in addition at least one of the (x_i){i=0,…,k} and (x_i){i=k+1,…,n} is non-zero,
- then the IRR exists and is unique.
Which of the following cash flow streams should we choose? Prevailing interest rates are 10%.
i) (-1,2)
ii) (-1,0,3)
PV criteria chooses (ii) but IRR chooses (i).
lec 1, page 6
Face value of a bond?
Coupon rate?
Emission price?
Par value?
Reimbursement price?
Maturity?
(aka nominal) this is the amount with which computations regarding the bond are made.
(yearly) coupon payment / face value
Price paid for a bond when it is emitted/created/first sold. Usually it is taken to be equal to the face value. In that case we say the bond is emitted at par value. If emission price is below face value, we say it is emitted below par value.
Reimbursement price is the amount paid back at maturity of a bond (excluding potential simultaneous coupon payment)
End date of the contract
Clean price of a bond?
Dirty price of a bond?
clean price := present value - accrued interest (%)
dirty price:=present value
where
accrued interest:=(#{days since last coupon} / #{days in current coupon period} ) * (coupon rate per period)
Purchase bond on may 8th, maturing august 15th several years from now. Coupon 9% and coupon payments made twice a year on Feb 15th and Aug 15th.
What is the accrued interest on May 8th?
Days in month: Jan 31 Feb 28 (29 if leap year. assume leap year) Mar 31 Apr 30 Mai 31 Jun 30 Jul 31 Aug 31 Sept 30 Oct 31 Nov 30 Dec 31
Accrued interest = 83/(83+99) * 4.5% ~ 2.05%
lect. 2
YTM?
Yield to maturity of a bond is the interest rate that makes the present value of all associated future payments equal to the current value of the bond.
Note YTM is nothing but the IRR of the bond at its current price.
Derive the relationship between YTM and price for a bond with face value F, m coupon payments of c*F/m every year and n coupon periods remaining.
What properties does P(lambda) have?
P=Sum(cF/m(1+lambda/m)^{-k} ; k=1,…,n) + F(1+lambda/m)^{-n}
=cF/lambda(1-(1+lambda/m)^{-n})+F(1+lambda/m)^{-n}
This describes the price-yield curve.
i) P non-increasing
ii) If lambda=c, then P=F. Bond is “par bond”.
iii) P is convex
iv) |dP(0)/dlambda|=n(n+1)cF/(2m^2)+F*n/m, i.e. bonds with longer maturities are more sensitive to variations in yield
Duration of a fixed-income instrument?
Bounded?
Can maturity=duration?
Weighted average of the times at which the cash-flows of the instrument occur.
(t_i){i=0,…,n} with associated present values (PV{t_i}){i=0,…,n}, then the Duration is:
D:=Sum(PV{t_i}*t_i) / Sum(PV_{t_j})
Yes, above by t_0 and below by t_n since convex comb between t_0 and t_n.
For zero-coupon bonds: maturity=duration
Interpr: Weighted length of time one has to wait in order to receive the security’s payments.
Macaulay Duration?
Modified Duration?
Relationship of modified duration and yield
D_t=1/PV_t * Sum( (k-t)/mc_k(1+lambda/m^{k-t}) ; k>t ), where PV_t=Sum( c_k*(1+lambda/m)^{k-t} )
D^M:=D*(1+lambda/m)
D^M_t = -1/PV_t * dPV_t/dlambda
Consider bond with maturity =10y, coupon rate=6%, face value=100, YTM=6%, PV_0=100, what is the modified duration?
How does the value change when YTM changes to 6.1%?
Approximate the change to the first order
YTM changes to 8%?
Compare to approx
lect 2, page 6
D_0^M=1/(1.06)(Sum( 6i(1.06)^{-i} ; i=1,…,10) + 10010/1.06^{-10})~7.36
PV_0(0.061)=Sum( 6/1.061^{-i} ; i=1,..,10) + 100/(1.061)^{10}~99.267
dPV_t(lambda)=PV_t(lambda+dlambda)-PV_t(lambda)=dPV_t/dlambda(lambda)*dlambda+o(dlambda)=-D_t^M(lambda)*PV_t(lambda)*dlambda+o(dlambda) then dPV_0(0.06)~0.736
PV_0(0.08)=Sum(6/(1.08)^i ; i=1,..,10)+100/(1.08)^{10}~86.58
Convexity of fixed-income?
Specify for m payments per year for n periods
C_t(YTM=lambda)=1/PV_t*PV_t’‘(lambda)
C_t=1/PV_tSum( (k-t)(k-t+1)c_k/[m^2(1+lambda/m)^{k-t+2}] ; k>t), where PV_t=Sum(c_k/(1+lambda/m)^{k-t} ; k>t)
2nd order approx of PV_t
dPV_t=-D_t^M(lambda)dlambda+0.5PV_t*C_t(dlambda)^2+o(dlambda^2)