Its not that big of a surprise that the computer would get rid of gold and favor US bonds with the additional 1879-1926 period. In that period (gold standard) bonds were a better hedge. They returned a lot more than gold and were pretty stable (no losing months). What's surprising is that the stock allocation held steady at 20%.
But this also shows the importance of building an 'all wheater' allocation instead of curve fitting things. Anyone who got rid of gold and favored bonds, in 1926, missed out on the significant advantage that gold had from 1926 to 2016 as the Great Depression hit (and the dollar was devalued) and a paper money system started to emerge. In this fiat world the value of gold as an hedge increase and its Sortino/Sharpe boosting effect was significant
But this also shows the importance of building an 'all wheater' allocation instead of curve fitting things. Anyone who got rid of gold and favored bonds, in 1926, missed out on the significant advantage that gold had from 1926 to 2016 as the Great Depression hit (and the dollar was devalued) and a paper money system started to emerge. In this fiat world the value of gold as an hedge increase and its Sortino/Sharpe boosting effect was significant