With 14 exchange traded funds (ETFs) brought to market in the last 20 months, Global X Funds on Tuesday reached the $500 million threshold in assets under management.

The milestone supports a recent BlackRock report that lists Global X Funds as the fastest-growing ETF provider in the United States, with an increase of 318% year to date.

The largest fund in the family is the China Consumer ETF (CHIQ), which in nine months has grown to more than $100 million in assets, according to a Global X news release.

The top-performing fund, named a Wall Street Journal “Category King” for August 2010, is the Global X/Interbolsa FTSE Colombia 20 ETF (GXG), whose cumulative performance has exceeded 170% since inception in February 2009.

“Our fast pace of growth speaks directly to the relevance these products have had with investors,” said Bruno del Ama, CEO of Global X Funds, in a statement.

Also Tuesday, Strategic Insight (SI), a business information provider to the fund industry, reported that international emerging markets equity ETFs were the leaders in net inflows in August. They were followed, at a distance, by corporate high-yield bond ETFs, gold ETFs, and income and growth ETFs, echoing the split in the traditional mutual fund market between either safe-haven investments at one end of the spectrum and higher-risk investments at the other end, according to SI.

SI also estimated that investors withdrew a net $778 million from U.S. ETFs in August, the first month to see aggregate ETF net outflows since January 2010. US ETF assets ended July at $812 billion.

“The increasing varieties of ETFs are providing investment instruments to meet a wide range of investor needs. That sort of innovation and flexibility should help drive further growth in the ETF market,” said Loren Fox, a senior research analyst at Strategic Insight, in a statement.

In other Global X Funds news, Global X Funds Lithium ETF (NYSE Arca: LIT) traded more than 450,000 shares on its opening day, July 23, making it one of the most successful ETF launches this year.

Read Vaughan Scully’s column published September 1, from the archives of InvestmentAdvisor.com.