11.5 For a price-weighted index, if one constituent stock offers a 2-for-1 split, the value of the index after stock split would:
A. Increase
B. Decrease
C. Remain the same
Correct Answer: C
A property unique to price-weighted indexes is that a stock split on one constituent security changes the weights on all the securities in the index. To prevent the stock split and the resulting new weights from changing the value of the index, the index provider must adjust the value of the divisor. This adjustment results in changing the divisor so that the index value is therefore remain the same.
加粗这句话如何理解？为什么要保持index的价值不变？
