Choosing Discrete or Continuous Returns for the Sharpe Ratio
Summary
The document addresses whether the Sharpe ratio should use discrete returns or continuously compounded returns. Its answer distinguishes the context: discrete returns are customary for client reporting, while the choice generally has little impact in a backtest. A second response describes the inputs as the realized portfolio return and standard deviation over the period.
The guidance is brief and does not give a derivation, example, or quantitative comparison of the two conventions. It also leaves details such as return frequency and annualization unspecified. The practical takeaway is to use a convention appropriate to the reporting purpose and apply it consistently, while recognizing that the stated equivalence in backtests is a general observation rather than a guarantee for every dataset or horizon.
Key ideas
- The document recommends discrete returns for client-facing Sharpe ratio reporting.
- It says the return convention usually makes little difference in backtesting.
- The ratio uses realized portfolio return and standard deviation over the measurement period.
- The guidance does not specify frequency, annualization, or conditions where the conventions may diverge.
Tags
Full text
# Sharpe ratio: discrete or continuous returns?
# Sharpe ratio: discrete or continuous returns?
The Sharpe ratio is known as $$SR=\frac{\mu-r_f}{\sigma}$$ Are these values calculated from discrete or continuously compounded returns?
## Answer by Helin (score 5, accepted)
https://quant.stackexchange.com/a/30472
For client reporting purposes, it is customary to use discrete returns. For backtesting, it pretty much make no difference.
## Answer by vonjd (score 1)
https://quant.stackexchange.com/a/30471
These are the realized return and standard deviation for the portfolio over the period.
Source: Paul Wilmott on Quantitative Finance, sec. ed., p. 329-330Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.