Gold's correlation to real rates is subject to regime shifts. Strategists at TD Securities find that expectations for Fed funds help to explain the regime. 

Momentum is now the winner's trade in gold

“The monthly correlation between gold prices and real rates tends to deteriorate during hiking cycles, which suggests that gold's recent disconnect against real rates is consistent with historical precedents.”

“With 86% of momentum signals pointing long in gold over the past 60d, the charts continue to favor higher gold prices.”