Can someone explain portfolio performance on whalewisdom dot com?

Hi all,

There is an interesting site whalewisdom.com that tracks and does some calculations on hedge funds using publicly available data. But I have no idea what it is actually showing. Let me take an example, DE Shaw page of this site:
whalewisdom.com[/]filer[/]d-e-shaw-co-inc
(delete brackets; sorry can't post links)

If you scroll down to 'Portfolio performance', you will see some metric on DE Shaw's performance. Though I know hedge funds have not been doing great for the past couple of years, the metric looks surprisingly bad for a top fund.

Does anyone have an insight into how the site computes the metric and what it actually means?

One a second note, is it a good site in any way?

Thanks!!