ETF investors displayed an overwhelming preference for gold even though its 7.1-percent gain for the year meant that it underperformed its precious metal peers — silver, platinum and palladium — which gained 9 percent, 9.9 percent and 7.5 percent respectively.

“Gold is special,” Brooks explained. “ETF investors in gold tend to focus very much on the big structural issues. They are less affected by short-term news. They don't really care if the FOMC [Federal Open Market Committee] is talking about the possibility of ratcheting back on quantitative easing at the end of 2013. They are really focused on the fact that US debt is growing and that the US doesn't yet seem to have a plan to deal with the debt issue in a serious way.”

“They [gold ETF investors] are very focused on Europe and the structural problem of competitive Southern European countries and Germany and what that may imply for the euro longer term. And until they see some kind of fix for that they are going to want to hold onto their gold ETFs. So they are very focused on the big picture,” he added.

Brooks said there is really no relationship between the gold price and flows into ETFs, except perhaps how much is purchased at a given time. Investors buy more when gold prices decline. When the price rises, sometimes they buy and sometimes they wait, he said.

ETF investors have earned the moniker “sticky money” for a reason. They do not generally take a tactical approach — such as abandoning gold for another metal that may be the hot commodity of the moment — to their investments in the market.

Some have suggested that the gold market is not readily attracting new investors. Brooks said he would argue that new players are entering the gold ETF space based on the growth in AUM over the past several years.