Offer your thoughts or opinion on the input financial query or topic using your financial background.

Will my current employer find out if I have a sole proprietarship/corporation?
Tell your employer during your initial contract Terms of Service discussions.  Ordinarily, this is boilerplate but you should ask for a rider in your contract which says - in some form - I already have IP, I will continue to work on this IP in my own time, and any benefit or opportunity derived from this IP will continue to be entirely mine. I requested exactly such a rider when I took up a new job just over a year ago and my employer was extremely accommodating.  That I already had a company in which that IP could reside actually made the process easier. As @JohnFX has already mentioned, not telling your employer is both unethical as well as storing up potential legal hassles for you in the futre.