同求

不知道是不是市账比，在Richardson的文章里看到的

1. Balance value /  stock value
2. Among firms with the highest risk of distress, the difference in returns between high and low B/E securities is more than twice as large as the return in other groups, and is driven by extremely low returns on firms with low B/M.

The index is about risk based explanation of the book to market premium.