Hedge fund SHK Asset Management liquidated a U.S. gold futures position this week valued at over $850 million, more than 10 percent of the main U.S. futures market, the Wall Street Journal reported on Friday.

As a result of the move, which was made on Monday, the number of gold contracts on CME Group Inc.'s Comex division plunged by more than 81,000, to about 500,000, in their biggest single fall ever, the WSJ reported. It said an average daily move is about 3,000 to 5,000 contracts.

Daniel Shak, who runs the $10 million fund, told the newspaper that the trade had been profitable for him for years, but it stopped working and the exchange kept raising his margin requirements, forcing him to put up more money.

Shak said that when the exchange raised it by 25 percent on Monday, he decided to cut his losses and end the trade, the newspaper said.

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