Dynamic portfolio selection under range value-at-risk with logarithmic returns
Hui Mi, Yuzhe Pan, Zuo Quan Xu
Abstract
This paper studies continuous-time portfolio selection under Range Value-at-Risk (RVaR), with both portfolio performance and risk evaluated in terms of logarithmic returns. We formulate a mean--RVaR problem in a continuous-time financial market and reduce the dynamic optimization to a static quantile problem. Using quantile representation, Lagrangian optimization, and convexification, we characterize the optimal terminal wealth through the convex envelope of an RVaR-specific transformed weighting function. The RVaR-specific convex envelope exhibits two distinct geometric configurations. Under Scenario~1, the terminal wealth has a VaR-type structure: the minimum-RVaR payoff is digital-option-like, whereas for $0<λ<1$ it consists of two growth-optimal regions separated by a constant-payoff region. Under Scenario~2, the convex envelope is determined either by a supporting line connecting an interior contact point to the endpoint or by a common supporting line with two interior contact points, leading to a richer multi-region payoff structure. We further show that the RVaR solutions reduce to their VaR and Expected Shortfall (ES) counterparts as $β\downarrowα$ and $α=0$, respectively. Under constant investment opportunities, we also derive closed-form wealth processes and replicating portfolio strategies. Numerical results show that the effects of $(α,β,λ)$ on risky-asset exposure are nonlinear and generally non-monotone. In particular, when $α>0$, pure minimum-RVaR optimization may assign zero terminal wealth in sufficiently bad states because the extreme quantile region $[0,α)$ is excluded from the RVaR criterion. These results clarify how interval-based quantile risk control shapes state-dependent portfolio payoffs and connects RVaR with its VaR and ES limiting cases.
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