Once you get your head wrapped around derivations you can toy with different asset allocations that might broadly yield similar reward. Potentially using deviations in those as a indicator of assets that might be relatively cheap/expensive.
Consider for example 50/50 stock/gold barbell. That's like two far extremes with a fulcrum that's like a bond bullet. So instead of 50/50 stock/bond you might hold 75/25 stock/gold to similar effect (75/25 stock/gold does however tend to have higher interim volatility).
Taking that a step further instead of 75% stock, holding 15% XIY/60% bonds is similar ... and instead of 60% bonds perhaps hold 30/30 stock/gold barbell.
Such that 50/50 stock/bond might instead be held as 15% XIV, 30% stock, 55% gold. If the stock pays no dividends, such as BRK-A, then collectively that 15/30/55 XIV/BRK-A/Gold might yield similar reward to 50/50 stock/bond, but with little/no regular income flows that might otherwise have been taxed. And comparing that with a conventional 50/50 along the way might at times indicate when one or the other was relatively cheap/expensive (and by further inspection that might reveal one or another of the individual assets to be 'out-of-kilter' and perhaps actionable (rearrange portfolio to potentially benefit from such deviations)).
News 
Market Data 
Discover 
