I noticed this problem last week, but thought somebody else would notice it. When running the screener in the past, it gets the dates wrong. For example (real case)
Rank data as of 05/20/17, Start Date: 05/22/17, End Date: 05/15/17
The end date is a week before the start date! The end date should be today (5/27/2017). Without detailed analysis, it appears gains become losses, and losses become gains.
I’m not sure how to reproduce the problem, but it’s likely to be similar to the following processes. (1)run backtest up to current date (2) display last weeks selection (3)select date 1 week earlier than now and run screener. This last stage is likely to have the problem. I hope this helps.
David