Via Energy and Gold.com:

Gold finished the week strong with a nearly $40 rally between Wednesday morning and Friday's close on the back of the Federal Reserve's decision to keep interest rates on hold. The CFTC Commitments of Traders Report helps to explain the sharp reversal in gold after weeks of gold prices dribbling lower:

 

Gold_COT_9.18.2015

Small speculators remain short at near record levels while large speculators hold a very modest sub-40,000 contract net long position. These are extreme positioning levels from which many previous rallies have occurred:

 

Gold_CoT_Chart

If Large Speculators were to revert to mean positioning levels (roughly 100,000 contracts net long) gold would likely have to rise to at least $1,200/oz.

Moreover, the next wave of the rally which began in late-July should also target the $1180-$1200 area which lines up with previous support and the 200-day moving average:

 

Gold_9.18.2015

This medium term target for gold would be negated in the event of a move back below $1117/oz.