Gold bar
Gold bar Photographer

The price of gold extended losses Thursday after the Chicago Mercantile Exchange, the world's largest derivatives market, raised margin requirements on gold futures for the second time in a month.

Gold peaked Tuesday at $1,911.46 per ounce and has been falling since on a combination of profit taking, economic data showing strength in some sectors of the U.S. economy -- thus tamping down resurgent fears of a double-dip recession -- and hopes that the head of the nation's central bank may be about to signal an intention or at least willingness to support the market.

The Chicago Mercantile Exchange's move follows similar steps earlier in the week by the Shanghai Gold Exchange and the Hong Kong Mercantile Exchange.

In morning trading, gold for December delivery, the most actively traded contract on the Comex division of the New York Mercantile Exchange, fell 2.44 percent to $1,714.40. Spot gold was down to $1,722.36.

Investors have cashed in on gold's latest rally after the yellow metal surged nearly 20 percent in early August to record highs at $1,911.46 an ounce.

In a sense the decline is just subtracting the frothy increase (from the market), Mitsubishi analyst Matthew Turner told Reuters. That increase has been going on since around $1,600 an ounce, so it is hard to see where the bottom lies.

To be convinced you'd seen the top of the market you would have to see more signs of the issues that had lifted gold being resolved, such as the euro zone crisis, and U.S. growth coming back, said Turner.