单选题 Consider the following information:
Assume an investor acquires 300 shares of a $ 40 stock for a total cost of $12000. There is a 50% initial margin requirement. If the stock price increases to $50 a share, the equity is:

A. 60%.
B. 70%.
C. 80%.

【正确答案】 A

【答案解析】If the stock price increases to $50 a share, the equity is 60%. Total market value of position: 300×50=15000. Initial margin =50%×12000 =6000. Equity =15000-6000=9000. 9000/15000=60%.