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University of Pennsylvania

A Sharper Ratio

Abstract

dc:description.abstract

The Sharpe ratio is the dominant measure for ranking risky assets and funds. This paper derives a generalized ranking measure which, under a regularity condition, is valid in the presence of a much broader assumption (utility, probability) space yet still preserves wealth separation for the broad HARA utility class. Our ranking measure, therefore, can be used with ``fat tails'' as well as multi-asset class portfolio optimization. We also explore the foundations of asset ranking, including proving a key impossibility theorem: any ranking measure that is valid at non-Normal ``higher moments'' cannot generically be free from investor preferences. Finally, we derive a closed-form approximate measure (that can be used without numerical analysis), which nests some previous attempts to include higher moments. Despite the added convenience, we demonstrate that approximation measures are unreliable even with an infinite number of higher moments.

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Zhang, Xingtan
Advisor dc:contributor.advisor
  • Kent Smetters

Rights

dc:rights
Statement dc:rights
  • Xingtan Zhang
Language dc:language
en

Identifiers

dc:identifier.*
Repository record dc:identifier.uri
https://repository.upenn.edu/handle/20.500.14332/32740
OAI identifier oai:identifier
oai:repository.upenn.edu:20.500.14332/32740

Chain of custody

source
Harvested from
University of Pennsylvania
Base URL
repository.upenn.edu/server/oai/request
Last updated
2026-07-24
Source record
OAI-PMH GetRecord
related terms
citation

Zhang, Xingtan. A Sharper Ratio. 2013. https://repository.upenn.edu/handle/20.500.14332/32740