The exchange traded fund (ETF) that tracks the S&P 500, SPDRs (SPY) added $20.7 billion in assets from Sept. 14 to Sept. 21, according to the American Stock Exchange (AMEX).

There are only two other ETFs in the world that have more than $20 billion in assets. The iShares MSCI EAFE Index (EFA) has $47.6 billion, and iShares MSCI Emerging Markets Index (EEM) has $20.9 billion, says Matt Hougan for Index Universe. SPY now makes up 16% of total U.S. ETF industry assets, and is larger than the smallest 491 ETFs combined. With an expense ratio of 0.1%, it grosses $91.6 million annually in fees.

For full disclosure, some of Tom Lydon’s clients own EEM.

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