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Investment Math edited untitled.md
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* Assuming the price trajectories are smooth, the value of the continuously rebalanced portfolio is the solution of:
\[\frac{dV_{rb,u}}{V_{rb,u}}=0.5\,\frac{dp}{p},\]
and this is just:
\[V_{bh}(p)=p^{0.5},\] \[V_{rb}(p)=p^{0.5},\]
assuming standard college calculus applies.
Both value functions equal \(1\) for \(p=1\) since both portfolios are initialized with one dollar. As soon as the price deviates from one, the rebalanced portfolio has an active position versus the buy-and-hold portfolio which has the wrong sign (underweight if the price has gone up, overweight if the price has gone down).