I have to agree, I like the familiarity of letter grades, but I don't think they have the descriptive power to do what your propose. We'd probably be better off with something graphical in nature (praise be to Edward Tufte and his kind). What also comes to mind is something similar to the workplace "Expecancy Theory" with Willing (+/-) vs Able (+/-) plotted on a 2x2 chart/table >> so what were the letter grades supposed to help us do? If they should help us guide investment decisions, then you could ultimately simplify all the analyzed data to a Expected to Increase in Price (buy or option to buy) vs Future Outlook Too Uncertain (essentially hold or consider alternate investments) vs Expected to Decrease in Price (sell or short sell).
I have to agree, I like the familiarity of letter grades, but I don't think they have the descriptive power to do what your propose. We'd probably be better off with something graphical in nature (praise be to Edward Tufte and his kind). What also comes to mind is something similar to the workplace "Expecancy Theory" with Willing (+/-) vs Able (+/-) plotted on a 2x2 chart/table >> so what were the letter grades supposed to help us do? If they should help us guide investment decisions, then you could ultimately simplify all the analyzed data to a Expected to Increase in Price (buy or option to buy) vs Future Outlook Too Uncertain (essentially hold or consider alternate investments) vs Expected to Decrease in Price (sell or short sell).