Just as we can predict the relationship between spot and futures prices, there are similar
ways to determine the proper relationships among futures prices for contracts of different
C H A P T E R
2 2
Futures
Markets
789
maturity dates. Equation 22.2 shows that the futures price is in part determined by time
to maturity. If the risk-free rate is greater than the dividend yield (i.e., r
f
> d ), then the
futures price will be higher on longer-maturity contracts and if r
f
< d, longer-maturity
futures prices will be lower. You can confirm from Figure 22.1 that in 2013, when the
risk-free rate was below the dividend yield, the longer-maturity S&P 500 contract did
have a lower futures price than the shorter term contract. For futures on assets like gold,
which pay no “dividend yield,” we can set d 5 0 and conclude that F must increase as
time to maturity increases.
To be more precise about spread pricing, call F ( T
1
) the current futures price for delivery
at date
T
1
, and F ( T
2
) the futures price for delivery at T
2
. Let d be the dividend yield of the
stock. We know from the parity Equation 22.2 that
F(T
1
) 5 S
0
(1 1 r
f
2 d)
T
1
F(T
2
) 5 S
0
(1 1 r
f
2 d)
T
2
As a result,
F(T
2
)/F(T
1
) 5 (1 1 r
f
2 d)
(T
2
2T
1
)
Therefore, the basic parity relationship for spreads is
F(T
2
) 5 F(T
1
)(1 1 r
f
2 d)
(T
2
2T
1
)
(22.3)
Equation 22.3 should remind you of the spot-futures parity relationship. The major difference
is in the substitution of F ( T
1
) for the current spot price. The intuition is also similar. Delaying
delivery from
T
1
to T
2
assures the long position that the stock will be purchased for F ( T
2
) dol-
lars at
T
2
but does not require that money be tied up in the stock until T
2
. The savings realized
are the net cost of carry between T
1
and T
2
. Delaying delivery from T
1
until T
2
frees up F ( T
1
)
dollars, which earn risk-free interest at
r
f
. The delayed delivery of the stock also results in the
lost dividend yield between T
1
and T
2
. The net cost of carry saved by delaying the delivery is
thus r
f
2 d. This gives the proportional increase in the futures price that is required to com-
pensate market participants for the delayed delivery of the stock and postponement of the pay-
ment of the futures price. If the parity condition for spreads is violated, arbitrage opportunities
will arise. (Problem 19 at the end of the chapter explores this possibility.)
To see how to use Equation 22.3, consider the following data for a hypothetical contract:
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