If you want to read useful academic papers about trading there is one author in particular who is actually not bad - Zura Kakushadze. Most of his stuff is applicable to mid-frequency trading, not HFT. He worked at WorldQuant (reputable trading firm) and the founder of WQ, Igor Tulchinsky, is a coauthor on one of his papers.
Example of a pretty interesting and accessible one - is "101 Formulaic Alphas" [0].
Example of a pretty interesting and accessible one - is "101 Formulaic Alphas" [0].
[0] - https://arxiv.org/pdf/1601.00991.pdf