What are some of the most reputable journals in which someone might publish studies regarding securities markets, banking, and brokerages?
Here's an overview with links: https://en.wikipedia.org/wiki/Category:Finance_journals And the Willmott Magazine seems to be good too: https://wilmott.com/category/magazine/ I've no experience with any of them
I suggest you the long buy from oppenheimer, chief equity at Goldman, he makes plain english explanations and refer to a lot of macroeconomic interesting papers in the notes, then you can narrow to find specific topics from the link above, i suggest you this approach because if you do not have clear what to look into is a rabbit hole. Most important skill is thinking critically doubting of the facts presented, leaving to the paper the burden to convince you