The 2012 year-end asset total, just shy of an all-time record of $1.350 trillion reached on Thursday, Dec. 20, also reflects the rise in global stock markets last year. The Dow, for example, rose 7.3 percent.

Of the $188 billion in 2012 inflows, $151 billion, or 80 percent of the total, came from the three biggest firms: BlackRock's iShares, State Street Global Advisors and Vanguard.

Last year's asset-gathering winner was the SPDR S&P 500 ETF (NYSEArca: SPY), the biggest ETF in the world. It pulled in $15.77 billion, or more than 8 percent of the total asset haul.

The Nos. 2 and 3 funds: the Vanguard MSCI Emerging Markets ETF (NYSEArca: VWO) and the iShares MSCI Emerging Markets Index Fund (NYSEArca: EEM), both gathered about $10.5 billion.

Bond ETF assets grew quite sharply in 2012, and the launch of Bill Gross' Pimco Total Return ETF (NYSEArca: BOND) on March 1 kept the phenomenon in sharp focus throughout the year.

Bill Gross' Pimco Total Return ETF (NYSEArca: BOND), the second-most-successful ETF launch in history after the bullion fund SPDR Gold Shares (NYSEArca: GLD), ended 2012 as the 10th-most-popular fund. It gathered $3.77 billion and ended the year with $3.87 billion in assets, making it the most successful fund launch of 2012.

GLD, the world's second-biggest ETF—with assets of $72 billion—ended the year as the No. 5 fund, with inflows of $5.75 billion.

The Top 10 list included fixed-income ETFs such as the iShares iBoxx $ Investment Grade Corporate Bond Fund (NYSEArca: LQD) and the iShares iBoxx $ High Yield Corporate Bond Fund (NYSEArca: HYG). LQD added $6.85 billion, while HYG pulled in $4.5 billion.

Overall, bond funds pulled in around $56 billion, or about 30 percent of the total asset haul.