Gold, up 29% in 2016, could be headed here next

Molten gold pours from a crucible into a heated mold after refining at the Kaloti Jewellery factory in Sharjah, United Arab Emirates.
Duncan Chard | Bloomberg | Getty Images

Gold does well when times are bad, or uncertain — and when the Fed looks sidelined.

Analysts say the rally in the precious metal, which has taken it close to a key technical challenge, could get another push higher if it looks like the Fed will stay on hold due to soft U.S. data or international conditions, or both.

Big investors are piling into gold, and that suggests its move up may not be just a flash in the pan. Bill Gross on Wednesday declared he now likes gold and he's following DoubleLine CEO Jeff Gundlach, and investors George Soros and Stan Druckenmiller.

But to really determine the direction for gold, there is one key thing to watch.