True enough!
John Murphy, in his Intermarket Analysis, likes to use the Relative Strength charts to compare the specific security to a benchmark, such as the S&P. When investing with a sector rotation approach, you want to beat the major indices, at least. Relative strength can also be predictive as to pending market changes, such as when comparing commodities to equities. Usually, these are inverse correlates, so when one is strong, the other is weak. That is a great help in deciding how to invest.
Currently, commodies are rapidly weakening against equities. That's bullish for the stock market.
Chico