ETFs with the highest cash inflows in June include SPDR S&P 500 (NYSEArca: SPY) with $3.6 billion, PowerShares QQQ (NasdaqGM: QQQ) with $1.4 billion and iShares iBoxx Investment Grade Corporate Bond Fund (NYSEArca: LQD) with $1.3 billion.

In contrast, funds with the largest outflows over the month include Vanguard MSCI SmallCap (NYSEArca: VB) with -$965 million, iShares Barclays 1-3 Year Treasuries (NYSEArca: SHY) with -$650 million and iShares FTSE China 25 (NYSEArca: FXI) with -$568 million.

At the end of June, there were 1,476 U.S.-listed fund products, or 15% more than the 1,288 products at the same time last year.

For more information on ETF asset flows, visit our ETF performance category.

Max Chen contributed to this article.