Barclays Global Investors (BGI) is continuing the expansion of its exchange-traded fund series when a new fund goes live today on the Chicago Board Options Exchange (CBOE).

The iShares S&P 100 index fund tracks the market performance of the top 100 companies in the US. Investors in iShares benefit from the diversification of index investing and can actually buy and sell units in the index fund itself, just like trading common stocks on a national exchange. This particular fund will only trade on the CBOE. iShares are distributed by SEI Investments Distribution Company.