Week 17 Day 7: The Verdict: Stocks for Wealth, Gold for Insurance

Stocks are the engine of long-term wealth. They earn money, grow earnings, and compound relentlessly. Gold is the safety net -- it helps when the engine stalls. A portfolio of 95% stocks and 5% gold has historically produced nearly the same return as 100% stocks with slightly less volatility. That is the sweet spot.

Here is the long-term simulated comparison (1972-2023): 100% S&P 500: 10.5% annual return, worst year -37%, maximum drawdown -51%. 95% S&P 500 + 5% gold: 10.3% annual return, worst year -35%, maximum drawdown -48%. 90% S&P 500 + 10% gold: 10.1% annual return, worst year -33%, maximum drawdown -44%. 100% gold: 7.7% annual return, worst year -33%, maximum drawdown -62% (real). The 5% gold allocation reduced the worst outcomes by several percentage points while costing only 0.2% in annual return. The 10% allocation provided more crisis protection at a 0.4% cost. Beyond 10%, gold increasingly drags returns without proportional risk reduction. The annual rebalancing is key: selling gold after it spikes (crisis periods) and buying stocks on sale produces the rebalancing bonus. Without rebalancing, the static gold allocation underperforms because gold's long-term return trails stocks. This is a discipline-dependent strategy.

The optimal gold allocation can be derived through both mean-variance optimization (MVO) and conditional value-at-risk (CVaR) frameworks. Under MVO using historical data (1972-2023), the maximum Sharpe ratio portfolio contains approximately 5-12% gold, depending on the estimation period. Using CVaR optimization (which penalizes tail risk more heavily), the optimal allocation rises to 8-15% because gold's left-tail protection receives greater weight. Black-Litterman models incorporating forward-looking views typically produce lower allocations (2-5%) because gold's expected return is lower than its historical average when starting from high price levels. The key insight from Qian (2011) on risk parity: allocating based on risk contribution rather than capital shows that even a 5% capital allocation to gold contributes only about 3% of portfolio risk -- suggesting that gold's diversification benefit is real but modest. The practical recommendation aligns across frameworks: 5% for investors focused on maximum growth, 10% for those who prioritize tail-risk protection and sleep-at-night comfort. Beyond 10%, the opportunity cost becomes too high relative to the marginal diversification benefit.