The current value of VIX and the daychange of the VIX (open vs close) as a filter for trading. I know this is already mentioned, but I personally cannot understand why that is not implemented. It is very important in this LOW Vol environment to stop trading some credit stuff. I do this manually every day, which is annoying. And wrong at some point as I do this not in the moment the trade would be placed. I like to port OO backests to TAT trading. As clean as it could be ported......