看跌期权是什么？在学习CFA过程中是不是需求把握这个常识呢？考题是怎样的呢？小编给你说说这个常识！

An investor writes a put option with an exercise price of $40 when the stock price is $42. The option premium is $1. At expiration the stock price is $37. The investor will realize:

A a loss of $2.

B a loss of $3.

C a profit of $1.

【答案及解析】A Because the stock price at expiration is less than the exercise price, the buyer of the put option will exercise it against the writer. The writer will have to pay $40 for the stock and can only sell it for $37 in the market. However, the put writer collected the $1 premium for writing the option, which reduces the net loss to $2.

【中心词汇 】put： 看跌期权

是指一类期权。即期权合约持有人有权力在合约规则的时刻按必定的价格向对方卖出根底财物。

B-S模型是看涨期权的定价公式，公式表明为：

S+PE(S，T，L)=CE(S，T，L)+L(1+γ)-T

移项得:PE(S，T，L)=CE(S，T，L)+L(1+γ)-T-S，将B-S模型代入整理得：P=L·E-γT·[1-N(D2)]-S[1-N(D1)]此即为看跌期权初始价格定价模型。

C—期权初始合理价格

L—期权交割价格

S—所买卖金融财物现价

T—期权有效期

r—接连复利计无风险利率H

σ2—年度化方差

N()—正态散布变量的累积概率散布函数