Stress free tool

I am looking to code an app. The focus for the app is to act as a “stress test” tool that is used for people’s stock portfolios. To basically show how there portfolios would react to certain market conditions. The apps focus is Risk Management, I want the app to be able to take customer’s portfolios and be able to give them a risk score based on the stocks they have and there market volatility. Another feature I would like to include is an “what if” feature basically showing what would happen to their portfolio or certain stock if “a certain move down or up” were to happen. I would need the app to allow users to be able to import their portfolios automatically.