When is the best time to launch your app?

I am developing a little app based on this idea.

The app is divided into two parts, the first part deals with the individual, and the second part deals with society.
The idea is to determine what trends are active in the society by measuring social mood.

How is social mood measured?
The stock market is one of the best indicators of social mood.
According to this principle, if you are feeling good you will buy stocks and if you are feeling fearful you will sell stocks.
The social media are even better tools, but it is hard to come up with some sort of global indicator.

I will be launching on product hunt next week to see if there is interest in such an app.
If you have any feedback, please let me know.
Would such an app be useful to you and is there a market for it?

Thank you