NO.PZ2023032701000072
问题如下：
May Stewart, CFA, a retail analyst, is performing a P/E-based comparison of two hypothetical jewelry stores as of early 2009. She has the following data for Hallwhite Stores (HS) and Ruffany (RUF).
HS has a simple capital structure, while RUF has a complex capital structure as a result of its outstanding stock options. Moreover, it had several unusual items that reduced its basic EPS in 2008 to $0.50 (versus the $0.75 that it earned in 2007).
Which P/E (trailing or forward) should Stewart use to compare the two companies’ valuation?
选项：
A. Leading P/E
Trailing P/E
No difference between the two methods
解释：
Because investing looks to the future, analysts often favor forward P/E when earnings forecasts are available, as they are here. A specific reason to use forward P/Es is the fact given that RUF had some unusual items affecting EPS for 2008. The data to make appropriate adjustments to RUF’s 2008 EPS are not given. In summary, Stewart should use forward P/Es.
老师，请问什么时候用trailing PE，什么时候用leading PE呢
