If your style is not math driven, fundamental investing are the strategies you can use.
BTW: the game of investing in the stock market has gotten harder because we have too much data with the historical data. (Efficient) markets tend to eliminate opportunities to make a profit.
Looking at 300 banks would be a good idea.
Value Investing
Value Investing is a fundamental investing strategy to value each company by going through the accounting/books of the company and buying companies that are theoretically undervalued.
Distressed Investing
Distressed Investing is the extreme version of Value Investing. Buy something that has a bad asset, a bad structure, and a bad holders: buy things when “what do they care what price they sell at”, which means you may be able to buy it at less than its worth.
Growth Investing
Growth Investing is a fundamental investing strategy to bet in the future growth of a company given its performance and technology: Tesla, Teledoc, etc.
Quality Investing
Quality Investing is a fundamental investing strategy to buy stocks even despite high prices that has the most dependable market share: Coke, P&G, etc.
Second-Level Thinking
A meta-level way of looking at decisions: “how many people know what I know.” Your strategy has to be both 1) DIFFERENT and 2) BETTER than what other people are doing.
“The correctness of a decision cannot be judged by the outcome.”