ETFs, which typically track market indexes, trade on exchanges like stocks. Exchange-traded funds have surged in popularity and now generate 35% to 40% of exchange trading volume, according to Morningstar Inc. Such funds sometimes are used by high-frequency traders, who buy and sell stocks and other assets at a rapid clip, making money on small moves.
SEC officials are zeroing in on “leveraged” ETFs, which amplify investor bets, often through derivatives. Derivatives are financial contracts with values linked to another asset. The funds typically offer double or even triple the return of an index, such as the Standard & Poor’s 500-stock index.
So-called inverse ETFs, which also can be leveraged, are like mirror-image indexes, gaining if the index falls and falling if the index gains.