Here are the lessons investors can learn from the 1999 IPO market

So far in 2019, companies have raised nearly $39 billion dollars in proceeds from public listings in the U.S. These proceeds are the highest since 2000, when U.S. listed companies raised about $67 billion in the same period. Kathleen Smith, founder of Renaissance Capital, Walter Isaacson, advisory partner at Perella Weinberg Partners and professor at Tulane, and CNBC's Leslie Picker join "Squawk Box" to discuss what is separating the listing frenzy 20 years ago from the IPO rust today.