Gold rebounds from four-week trough

Gold prices rose away from a four-week trough ahead of Fed Chair Janet Yellen's speech later today, with traders also closing their short positions after dipping earlier in the week. 

Gold last traded at $1,329.8 an ounce, up from the opening of $1,322.2, with an intraday high at $1,333.1, and a low at $1,321.4. 

Gold's recovery today comes as the dollar slips against main currencies while traders await Yellen's speech in the global central banks meeting in Jackson Hole. 

Rising speculation of a rate hike before the year end after bullish comments by Fed officials served to put gold down recently as it goes in opposite ways with interest rates. 

The dollar index, which tracks the greenback against an array of six main currencies, fell to 94.59 from the opening of 94.69, with a session-low at 94.48, and a high at 94.70, after the index hit its highest this week at 94.95.