Chart 2: Gold rallies during the two decade bear market (from 1980 to 2001, London P.M. Fix, in $).
The last two rebounds lasted about 34-35 months, so the current rally (if it started in December 2015) still has 8-9 months to align with the pattern. And since December 2015 gold jumped about 26%, so it has some room for further gains. If historical patterns hold, gold could reach almost $1,600 before continuing its secular downward move.
Please note that the above conclusions are generally in line with the analysis of the U.S. dollar cycles. The chart below plots the cycles in both of these assets together. The correlation is not perfect (the first half of the 1990s is a bit tricky), but it is substantial.
Chart 3: Bull and bear cycles in the U.S. dollar (Trade Weighted Index against major currencies) and gold (yellow line, London P.M. Fix, in $) from 1973 to 2018.
The greenback could weaken further in the medium term, but the secular bull market may be not over. It would imply that gold may continue its rally for a while before the day of reckoning will come. What is important is that the tax cuts are not deficit-neutral, so they will widen the fiscal deficit. The increase in the public debt will not only spur some safe-haven for gold acquisition, but it could also raise the dollar supply, contributing to the decline in the U.S. dollar. Since the USD seems to currently be at a decisive point or close to it, we should see either confirmations or invalidations of the above relatively soon.