The respective return/volatility ratios have been 47.8% and 43.8% suggesting that gold has slightly outperformed silver on a risk-adjusted basis.
We thought we would investigate which of the two commodities currently represents better value, based on a fair value assessment. The fair value of the commodities is based on a multiple regression analysis of their price on 22 driver variables including interest rates, stock indices, other commodities and exchange rates. The database is 6.5 years of daily prices sourced from eoddata.com.
The regression coefficients are multiplied by the current prices of the driver variables. Summed and added to the regression intercept, this gives a current estimate of fair value.
The driver variables for the gold price model, and the sensitivity of the fair value to those variables, is shown in the graph below –
(click to enlarge)
The positive correlation to the bond index (and negative correlation to the 30-year bond rate) is not surprising given that higher interest rates increase the opportunity cost of holding gold. This effect is exacerbated by the strengthening of the USD that could be associated with higher US interest rates.
For silver, we have:
(click to enlarge)
(The gold/silver index is the PHLX Gold/Silver Sector index of gold and silver mining companies: ticker XAU.)
The opposite impacts of US dollar index movements on gold (negative correlation to USD) and silver (strong positive correlation) can be seen from the above two graphs.
The current fair value of gold using this model is $1251, which is 4.8% above the current price of $1194. The fair value of silver using this model is currently $18.08, which is 14.2% above the current price of $15.83.
This analysis suggests that silver is currently better fundamental value than gold, with neither being assessed as overpriced.
We can also make an attempt at estimating the short-term price movement in each commodity using a lead indicator approach. The PHLX Gold/Silver Sector index has fitted reasonably well in this regard (to both indices) over the last 6.5 years. We assessed the relationship between six-week returns on XAU and subsequent six-week price movements of gold and silver. Based on the movement in XAU over the last six weeks, we have a projected decrease in the gold price over the coming six weeks of 1.7% with 4.0% decrease in the silver price.
Given that silver has the more volatile price, this suggests that for the short term, gold is the better option. A long gold/short silver pair trade would hedge out some of the downside in both commodities, but would be exposed to unanticipated US dollar strength.
A trading strategy based on the lead indicator model opens up the possibility of an alternative investment offering valuable diversification to a US-centric stock portfolio. Allocating 10% to gold traded using the lead indicator model would have increased the annualized return/volatility ratio from 101.2% (100% S&P 500) to 113.1% over the last 6.5 years. An allocation of 10% to silver would have given 110%. Allocating 5% to each of gold and silver would have provided a ratio of 112%.
SPDR Gold Trust (ETF) (NYSEARCA:GLD)
Direxion Shares Exchange Traded Fund Trust (NYSEARCA:NUGT)
Market Vectors Gold Miners ETF (NYSEARCA:GDX)
Market Vectors Junior Gold Miners ETF(NYSEARCA:GDXJ)
Direxion Shares Exchange Traded Fund Trust (NYSEARCA:JNUG)
Direxion Shares Exchange Traded Fund Trust (NYSEARCA:JDST)
iShares Silver Trust (ETF) (NYSEARCA:SLV)
Global X Silver Miners (NYSEARCA:SIL)
ProShares Ultra Silver (ETF) (NYSEARCA:AGQ)