M2 expansion is the prime driver of prices, after supply & demand. Normalize SPX, gold/silver, etc, to M2 and see that they all run in fairly horizontal channels. You can even see nominal GDP normalized to M2 having been flat initially and then transitioning into a downward sloped curve for the last few decades.
By normalizing, I mean [in TradingView] doing SYMBOL*23.16*10^12/M2SL (conceptually SYMBOL*M2SL[0]/M2SL). Most important items track close to M2's roughly 6.5%-7% annualized force of interest inflation rate (the quotient of the natural log of the ratio of price now to historical price, over the elapsed time between the prices).
7% inflation (FoI) -> wealth halflife of cash ≈ 10 years.