Rachev Ratio Indicator

[DerekMelchin]

Expected Behavior

Lean has a built-in indicator to compute the Rachev Ratio

Actual Behavior

Not implemented

Potential Solution

Add the Rachev Ratio indicator

Reproducing the Problem

N/A

System Information

N/A

Checklist

• [x] I have completely filled out this template
• [x] I have confirmed that this issue exists on the current master branch
• [x] I have confirmed that this is not a duplicate issue by searching issues

• [ ] I have provided detailed steps to reproduce the issue