Buy gold when the moving average of the ratio is rising. Sell gold and buy the SP when the ratio is falling. Confirm timing with the 65week moving average of gold prices. RESULTS: Buy gold in 1971—1972. Sell gold and buy the SP in 1980. Buy gold in 2001, sell gold in 2011, and buy gold in late 2018 and early 2019. Don't be surprised if ...