An options exchange has a number of European call and put
options listed for trading on ENCORE stock. You have been paying
close attention to two call options on ENCORE, one with an exercise
price of $52 and the other with an exercise price of $50. The
former is currently trading at $4.25 and the latter at $6.50. Both
options have a remaining life of six months. The current price of
ENCORE stock is $51 and the six-month risk free rate is 3% p.a.,
continuously compounded.
Required:
How would you exploit this situation to earn arbitrage
profits? You should assume the arbitrageur can borrow or lend at
the risk free rate, can short sell shares if necessary and does not
face any transaction costs.
Hint: For call options with different strike prices but the
same expiration date, the maximum difference between call prices is
C1 – C2 < (K2 – K1) e-rT where K2 > K1. You are expected to
employ the five-step proof method to demonstrate your arbitrage
strategies. When demonstrating the arbitrage opportunity, you will
need to consider different scenarios at time T, ie., if , ,
and.