As someone who has written about this previously [0], worked briefly in HFT before, and read dozens of papers on the subject, I can say with very high confidence that the results are not to be trusted. This paper, just like pretty much any academic paper on the subject, ends with a backtest on historical data, not a real system. Not only is it (very!) easy to overfit backtests (especially with so little data they are…
https://www.johndcook.com/blog/2011/06/21/how-to-fit-an-elep...
Edit down voters care to elaborate?