Session 13: Market Organization, Market Indices, and Market Efficiency Reading 56: Security Market Indices
LOS d: Compare and contrast the different weighting methods used in index construction
Assume a stock index consists of many firms who have recently split their stock. Which of the following weighting schemes will see a bias due to the impact of stock splits?
A) |
Unweighted price series. | |
B) |
Market value-weighted series. | |
C) |
Price-weighted series. | |
Firms that split their stock price will have the identical weight before and after the split in both the unweighted and the market value-weighted series. However, in the price-weighted series, large successful firms will lose weight within the index due to simply splitting their stock. This creates a downward bias in a price-weighted series. Standard and Poor’s 500 Index is a market value-weighted index. |