Book-to-market values是啥意思啊？

问题如下：

Fama and French (1996) added two risk factors beyond the market index to explain past average rates of return. Which of the following ratios is a risk factor in the FamaFrench empirical model?

选项：

A.

EBITDA to total sales

B.

Current assets to current liabilities

C.

Net profit to total assets

D.

Book-to-market values

解释：

D is correct. Book-to-market values

HML is the difference between the returns on stocks with high book-to-market values and those of stocks that have low book-to-market values.

中文解析：

D是正确的。Fama-French发现的有效因子包括size factor和value factor。其中value factor就是HML，也就是账面/市值比例高的股票的收益率减去账面/市值比例低的股票的收益率形成的因子。