Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Does an index have a currency?
From Wikipedia -  To calculate the value of the S&P 500 Index, the sum of the adjusted   market capitalization of all 500 stocks is divided by a factor,   usually referred to as the Divisor. For example, if the total adjusted   market cap of the 500 component stocks is US$13 trillion and the   Divisor is set at 8.933 billion, then the S&P 500 Index value would be   1,455.28. From a strictly mathematical perspective, the divisor is not canceling out the units, and the S&P index is dollar denominated even though it's never quoted that way. A case in point is that the S&P is often said to have a P/E, and especially an E, the earnings attributed to one 'unit' of S&P. And if you buy a mutual fund sporting a low expense ratio, you can invest exactly that much money (the current S&P index value) and see the dividends accrue to your account, less the fee.