Does studying accountancy helps in understanding stock market and investments?

Knowledge of Accountancy obviously helps you understand Financial Markets in a better way. This is the accountancy that generates the results of financial transactions. I mean because of accounting procedures Financial Statements are created. And Financial Statement is one of the main pillars for Stock Valuations subject to other factors. Therefore, knowledge of accountancy definitely helps you. 

I don't think so, cause being successful in stock markets and investment needs practice, skills, analysis and access to proper information in the right time.

A decrease in interest rates will prompt investors to move money away from the bond market to the equity market.

Although the relationship between the two if fairly indirect, they tend to move in opposite direction.