lower bound是什么意思？

A call option with a strike price of 60 will expire in 80 days. No cash payments will be made by the underlying asset over the life of the option. If the underlying asset price is 70 and the risk-free rate of return is 5.0 percent, the lower bound for an American call option and a European call option, respectively, are closest to A the lower bound for an American call option is 10; the lower bound for a European call option is 10.64. B the lower bound for an American call option is 10.64; the lower bound for a European call option is 10. C the lower bound for an American call option is 10.64; the lower bound for a European call option is 10.64. 为什么在题目里美式与欧式的价格会一样？还有一点就是为什么这里美式不提前行权？

01.单选题 Which of the following is least likely an appropriate use of the CFA designation? A. Jeremy Salyers, as a CFA charterholder, expects to outperform the market because CFA charterholders have on average outperformed their peers. B. Jeremy Salyers, CFA. C. Jeremy Salyers has earned the CFA designation by passing three exams, all three on his first attempts. 这个答案选A，但我觉得C也不对啊，通过考试就能获得CFA的designation吗？不是还需要有48个月的相关工作经验，以及两个持证人的推荐才可以使用CFA的title吗？

PPT23页，视频54分钟里的例题中，老师讲A选项和C选项都对。但是答案是C选项。那A选项到底是对还是错，如果错了的话错在哪里了？

16题 其实没用到PI 只是算三个选项中的组合哪个NPV最大是吗 谢谢

14题 capital 为什么分别是100和50？ 是初始投资减去当年折旧吗？ 此处的capital怎么定义的？

老师好，12题 cf=（s-c-d)(1-t)+d=(50-50*0.12-50)(1-0.3)+50 为什么不对呢

17.单选题 收藏 标记 纠错 Hitch changes its target capital structure to 70% equity and 30% debt from its original capital structure with 100% equity financing. Hitch has a large asset base, a 30% operating profit margin, and the average interest rate on debt is expected to be 5.0%. If Hitch makes the change to its target capital structure and EBIT is unchanged, what is most likely the impact on Hitch's net income and return on equity (ROE) respectively? A Decrease; Increase B No Change; Increase C Decrease ;Decrease 查看解析 上一题 下一题 正确答案A 您的答案A本题平均正确率：55% WACC难度：容易 推荐：      答案解析 You should be able to figure out this question with logic (without having to use calculations). The interest expense associated with using debt represents a fixed cost that reduces net income. However, the lower net income value is spread over a smaller base of equity capital, serving to increase the ROE. 问：没明白关联到哪个知识点，可否进一步讲解？

第15题所说的熊市不应该是市场不好的情况吗？市场不好的情况下为什么要扩大IPO？以及BC选项哪里错了？

希望解释一下第七题和第九题分别的选项