Sept 16 (Reuters) – A 60/20/20 portfolio strategy that includes 20% gold is a more resilient inflation hedge at a time when U.S. equities are offering historically low upside over Treasuries and investors are demanding higher yields for long-term bonds, Morgan Stanley (MS.N), opens new tab Chief Investment Officer Mike Wilson said on Tuesday. A 60/40 portfolio, which typically has 60% of its holdings in stocks and the remaining 40% in fixed income, counts on moves in the two asset classes to offset one another, with stocks strengthening amid economic optimism and bonds rising during turbulent times…