This page lets you simulate how much money you might make or lose in the stock market. It uses real S&P 500 data from January 1928 to April 2020 to simulate how your investment would have done in different time windows, and then displays the distribution of results you might have gotten if you had started investing at different points in time.
Future market behavior, of course, may not resemble past behavior.
This simulation may have serious bugs. I haven't tested it well.
SARS-CoV-2 may mutate and kill us all.
The APR input lets you compare how your investment might do compared to earning interest in a bank account.
The gray lines represent various percentile points of market performance.