I would like to have a notes field for each investment to include pertinent decision making information, such as why I got into the investment, when I should get out, etc.
Another feature I would like to see would be an investment property called Expected Return, which typically would be the sum of a set of possible returns and the probabilities of achieving those returns.
Here is an example: Let's say you buy Microsoft at $30. You might make projections of Microsoft returning different values based on what their actual earnings are reported relative to analyst estimated earnings.
Expected Return = 5%, probability = 0.25
Expected Return = 10%, probability = 0.45
Expected Return = 15%, probability = 0.30
The Expected Return for the security given these probabilities would be .05*.25+.1*.45+.15*.3 = 10.25%
You would need a way to enter the table of Expected returns, probabilities, and perhaps what they are based on (i.e. earnings for next quarter.)
Then you might have a portfolio optimizer that takes into account the single calculated expected earnings value (i.e. 10.25%) to help you determine asset allocation.
The software at the following site has a feature like this:
https://www.alphatheory.com/index.jsp?section=overview