Potential silly question - have all publicly traded companies ie common shares been the result of a past IPO?

I am new to investing, and I am now convinced that stocks are the long term choice as the best performing asset class... however I keep seeing people say “never buy an IPO” etc. Well, how did a company get on the stock exchange if they didn’t previously go public? What am I missing here? Or is the advice just something like - don’t immediately buy an IPO because it might drop. I am approaching this from a value-investing long term lens, ie don’t I want to get in as early as possible on what I think would be a future blue chip stock?

Submitted January 06, 2019 at 04:54PM by vinodragon http://bit.ly/2Vyz6Bq