The initial public offering, or IPO, was once a popular way to achieve massive returns for the average investor. This was never more true than in the 1990s, when an average of 409 companies went public each year, at an average market cap of roughly $600 million.
Since the dot-com boom went bust, IPO opportunities have somewhat dried up.
According to data from University of Florida Professor of Finance Jay Ritter, an average of just 117 companies went public per year throughout the 2010s.
Source Fool.com