问题如下:
The current price of stock ABC is $42 and the call option with a strike at $44 is trading at $3. Expiration is in one year. The corresponding put is priced at $2. Which of the following trading strategies will result in arbitrage profits? Assume that the risk-free rate is 10% and that the risk-free bond can be shorted costlessly. There are no transaction costs.
选项: Long
position in both the call option and the stock, and short position in the put
option and risk-free bond
Long position in both the call option and the put option, and short position in the stock and risk-free bond
C.Long position in both the call option and the risk-free bond, and short position in the stock and the put option
D.Long position in both the put option and the risk-free bond, and short position in the stock and the call option
解释:
ANSWER: C
Answers A and B have payoffs that depend on the stock price and therefore cannot create arbitrage profits. Put-call parity says that should equals . The call option is cheap. Therefore buy the call and hedge it by selling the stock, for the upside. The benefit from selling the stock if S goes down is offset by selling a put.
老师好,这道题按照答案C选项,我理解解题思路应该是下图紫色圈的部分:按照put-call parity算出来的C(均衡) =4.187,但目前市场上的C=3,所以就要long C(市场),short C(均衡),而short C(均衡)= -P-S+K,即选项C;
但是如果按照红色圈的部分:按照put-call parity算出来的P(均衡)=0.8128,但目前市场上的P=2,所以就要long P(市场),short P(均衡),而short P(均衡)= -C-K+S,所以这道题还有另外一种套利的方法,即long position in put option and stock, short position in call option and risk-free bond。(虽然答案里没有这个选项)
想和老师确认一下上面的理解是否正确?