quantopian / alphalens

Performance analysis of predictive (alpha) stock factors
http://quantopian.github.io/alphalens
Apache License 2.0
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cumulative_returns calculation no longer adjusts for periods > 1? #386

Open jeromeku opened 4 years ago

jeromeku commented 4 years ago

Problem Description

It seems that the plot_cumulative_returns_by_quantile function in the performance module is no longer adjusting for period > 1. I was under the impression that the cumulative returns are calculated as explained in issue #187 and here on the Quantopian forum. However looking at the latest master branch definition of this function shows that the period parameter is only being used to label the plot and NOT in the cumulative returns definition, which is calculated using the empyrical cum_returns function which calculated simple daily returns.

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