问题如下：
Stanley Kumar Singh, CFA, is the risk manager at SKS Asset Management. He works with individual clients to manage their investment portfolios.
A third client, Wanda Tills, does not currently own Walnut shares and has asked Singh to explain the profit potential of three strategies using options in Walnut: a long straddle, a bull call spread, and a bear put spread. In addition, Tills asks Singh to explain the gamma of a call option. In response, Singh prepares a memo to be shared with Tills that provides a discussion of gamma and presents his analysis on three option strategies:
Strategy 1: A long straddle position at the $67.50 strike option
Strategy 2: A bull call spread using the $65 and $70 strike options
Strategy 3: A bear put spread using the $65 and $70 strike options
选项：
A.$ 55.00.
B.$ 67.50.
C.$ 80.00.
解释：
B is correct.
The $67.50 call option is approximately at the money because the Walnut share price is currently $67.79. Gamma measures the sensitivity of an option’s delta to a change in the underlying. The largest gamma occurs when options are trading at the money or near expiration, when the deltas of such options move quickly toward 1.0 or 0.0. Under these conditions, the gammas tend to be largest and delta hedges are hardest to maintain.
老師
我們知道gamma最大就是當share price near exercise price or ATM的時候
我覺得這麼的圖一 也直接給出call delta 在股價是55元的時候最大為1
請問這題怎麼解釋 為何不用圖一來作答
謝謝
