I attach an old article by Dr.Brett N. Steenbarger on stationarity.
I believe all members interested by the Robot's design and concepts should study it carefully.
Indeed, I think the robots are using stationarity rules derived over one or more stationary windows of opportunity.
Neutral windows of opportunity like now are non-stationary (uncertain and whipsawing market).
Non-neutral signals detect rising stationarity early whether into mean-reversion or trend-following mode.
The trade timeframe is not fixed and is dependent on how long the new stationarity is active.
I haven't consulted Pascal about these assertions, so he's welcome to comment.
Billy

Stationarity.pdf